U.S. Conventional Prompt Global Strike: Issues for 2008 and Beyond (2008)

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2 Military Issues Defining conventional prompt global strike It is well accepted that the United States needs conventional strike capability, that such capability should be global in its reach, and that it should be usable on a timely basis. It is less clear, however, precisely how that should be translated into what the Department of Defense (DOD) calls “requirements.” How much reach is enough? How fast is prompt? The DOD has expressed its preferred answers, but the Committee on Conventional Prompt Global Strike Capability was asked for an independent assessment. How Should “Global” Be Defined? How Much Reach Is Enough? It can be argued that strike capability could be needed against targets any- where on the globe. However, even those who favor capabilities-based planning rather than planning tied to specific scenarios will acknowledge that it is unlikely that strikes will be necessary on outposts in Antarctica, Patagonia, or Tasmania, or even that the ability to threaten such strikes will be necessary. Further, if the world situation should change in this regard, there would likely be time for redeployment (over days or weeks). Because of such considerations, the laws of physics, and economic considerations, the committee concluded that it did not wish to limit consideration to systems that could strike any point on the globe within 1 hour, or even a number of hours. It was willing to make trade-offs on the matter. Thus, in what follows, “conventional prompt global strike (CPGS)” implies long-range coverage but not necessarily “global” coverage at any given time. 27 

28 U.S. Conventional Prompt Global Strike Decision; prepare Actionable warning for “instant (triggering event) response” Tw Ts Ta Te T0 Strategic Forces alerted; Execution Time of effect warning; final planning ordered preparations begins begin Execution time FIGURE 2-1  Time line for a case in which execution follows a substantial period of warn- ing, contingent decision, and preparation, with the final decision made quickly. NOTE: Ts—time of strategic warning; Ta—time at which forces are alerted; Tw—time of actionable warning; Te—time of execution order; T0—time of effect. Intelligence and command-and- control activities are critical factors in the overall time line for any CPGS system. The Figure 2.1 time between actionable warning, Tw, and the order to execute, Te, includes the time for bringing weapons to ready-to-launchb&w SOURCE: Adapted, with permission, from status. Paul K. Davis, Russell D. Shaver, and Justin Beck, 2008, Analytical Methods for Assessing Capability Options, RAND, Santa Monica, Calif., p. 61. © 2008 RAND Corporation. How Should “Prompt” Be Defined? Is “Within 1 Hour” a Good Criterion? The same type of question asked about the definition of “global” can be asked about the definition of “prompt.” Obviously, an instantaneous strike capability would be desirable if achievable. But what is feasible, valuable, and affordable? What Is Feasible? As discussed in detail in Chapter 4 of this report, global strike operations involve a long and complex end-to-end chain of activities. Figure 2-1 explains this chain of activity schematically for a case of particular interest. Two of the most important factors are execution time and the class of targets that can be effectively attacked. “Execution time” is the time between the President’s order to execute an attack (at a time Te) and when the target is affected (at a time T0). The figure envisions earlier strategic warning (at a time Ts) and an early contingent decision (at a time Ta) that initiates detailed preparations. When “actionable warning” occurs (i.e., when the triggering event occurs, at a time Tw), the final decision to proceed is made quickly (perhaps in tens of minutes, based on precedent, at a time Te), and execution begins.   his T assumes that neither aircraft nor missiles are launched prior to the President’s authorization to strike. 

MILITARY ISSUES 29 Both experience and an examination of possible futures with the DOD’s and the committee’s scenario-based analysis suggest that this case will be the norm for CPGS: crises and opportunities will seldom arise as complete surprises with tar- gets that merit a conventional “strategic” military strike “popping up.” The more important cases are likely to be ones in which events develop over time—perhaps many hours, days, weeks, or even months. As a result, considerable preparation, deliberation, and tentative decision making can occur ahead of time, even if final developments move rapidly—that is, even if execution itself is and needs to be fast (i.e., prompt). In such cases, execution time itself may be the limiting factor for timeliness. For example, there could be an advance policy decision to strike at a terrorist leader if he could be located, or at shipments of nuclear materials to a potential proliferator if these materials were identified and located. This said, the other factors are also critical to the mission’s success (and will sometimes deter- mine timeliness as well). If CPGS is to be pursued, all aspects of the end-to-end process must be pursued vigorously. Enablers (e.g., intelligence, command and control, and targeting) for CPGS capabilities are discussed later in this chapter. First, however, execution time, target type, and some other key operational fac- tors are addressed. In addition to execution time, a second key measure is the class of targets against which a CPGS can be used. These classes range from the less difficult (soft point targets such as people or stationary vehicles) to the more difficult (hard and deeply buried target complexes). Other factors (such as whether targets are moving) are also important, but Figure 2-2 uses these first two, execution time and target class, to make some important distinctions. Figure 2-2 is to be understood as follows. Consider first the solid contour marked “A.” This contour indicates that tactical aircraft or cruise missiles are usable for global strike in situations that permit execution times greater than a few hours and which involve targets that may be hard, and may even be buried, but that are not large-area deeply buried targets. This is the region below and to the right of contour A. If the launch platforms are not both located where they need to be and poised for action (e.g., if an aircraft carrier is in the appropriate general region but conducting exercises that impede mission execution), the execution time might be more like 10 hours; and if ships or submarines would need to deploy to new loca- tions, the execution time might be days (i.e., more like 100 hours than 10 hours). With existing systems, even the most distant target can be reached in the time it takes for a bomber to fly from Guam, Diego Garcia in the Indian Ocean, or the continental United States (CONUS)—perhaps 10 to 20 hours of actual flight time, plus whatever additional time is needed to generate tanker support. Moving upward in the figure to the light contour marked “B,” note that bombers could have the same range of execution times if they were forward deployed, but if not, execution time would be on the order of 10 to 20 hours (as just described). Bombers, however, would have more capability against complex deeply buried targets because of their great payload. 

30 U.S. Conventional Prompt Global Strike Target Character (increasing difficulty) Large, deep, No capability underground, ambiguous B Bombers Large, deep, underground A Tactical aircraft, cruise missiles C Ballistic or hypersonic Hard point cruise missiles target Point target 1 10 10 2 Execution Time (hours) FIGURE 2-2  A depiction of capability space for global strike. NOTE: The dashed lines with two-headed arrows indicate that the boundary moves rightward unless the platforms in question are appropriately deployed and postured. SOURCE: Adapted, with permis- sion, from Paul K. Davis, Russell D. Shaver, and Justin Beck, 2008, Analytical Methods Figure 2.2 for Assessing Capability Options, RAND, Santa Monica, Calif., p. 52. © 2008 RAND Corporation. color Suppose that the mission in question requires shorter execution times. Instan- taneous would be ideal, but according to Figure 2-2, the only feasible region is for relatively simple targets and times on the order of 1 hour or more; that is, the dotted contour marked “C.” The only weapon systems being contemplated for this region of the capability space for global strike are ballistic missiles and hypersonic cruise missiles.   n special circumstances, any of the contours could move leftward somewhat. If orders were I received ahead of time and missiles were at short range, strikes could occur in tens of minutes. If tactical air forces were already in the air and merely had to be diverted to a new target, they could fly 500 miles or so in roughly an hour. For planning purposes, however, more realistic times should be used. Many factors come into play, including maldeployment; being engaged in other missions or not being at a high state of alert; distance from the target; delays associated with receiving, interpret- ing, and verifying a presidential directive; or the need for detailed at-the-time planning to avoid air defenses, avoid collateral damage, and orchestrate (for some appreciation of such difficulties, see Michael R. Gordon and General Bernard E. Trainor, 2006, Cobra II: The Inside Story of the Invasion and Occupation of Iraq, Pantheon Books, New York, Ch. 9). Thus, the committee has treated “a few hours” as a reasonable analytic lower limit for normal air breathers and 1 hour as a reasonable lower limit for ballistic or hypersonic cruise missiles. 

MILITARY ISSUES 31 What Is Valuable? Would an Execution Time of 1 Hour Be Important? If a 1-hour execution time is feasible, then the next question is whether it would be of sufficient value to justify the required investment funds and priority. The answer is not immediately obvious; numerous past strikes have been accom- plished without such extreme promptness. Nonetheless, the DOD has argued strongly that the capability for prompt strike would be very important, and it has defined “prompt” as an execution time of 1 hour or less. The view of the Secretary of Defense has had firm supportive testimony from the Secretary of State and the Joint Chiefs of Staff. The committee, however, was charged to make an indepen- dent assessment, and it concluded that credible instances can readily be imagined for which a CPGS capability would be quite valuable. Specific scenarios can be useful in judging whether a capability is needed. The committee identified three scenario classes (see below), the concreteness of which aided discussion, each of which creates an argument for short execution times such as an hour. These scenario classes are as follows: 1. Terrorist leaders. The first scenario class envisions striking a gathering of terrorist leaders expected to be meeting in a particular location for a short period of time. This kind of information is sometimes obtained by electronic intercepts or by intelligence from operatives on the ground. Such a scenario is analogous to actual events from the past decade. In the 1990s, it was sometimes known that al-Qaeda leaders would be meeting, but the time and place were not known pre- cisely until late in the game. In one instance, the President had such intelligence but decided not to strike because of concerns about collateral damage. In another instance, the President authorized a strike in advance, but when the cruise missile subsequently struck the camp, Osama bin Laden was no longer there (having left perhaps several hours earlier according to some reports). During the first phase of the invasion of Iraq in 2003, intelligence reports purportedly located Saddam   embers M of the committee differed about which illustrative scenarios should be regarded as the most important and plausible. Some members resonated most with scenario classes 1 and 2, while having deep reservations about class 3. Others resonated with developing deterrence-enhancing capa- bility for class 3 scenarios, while being less persuaded about classes 1 and 2. Overall, the committee believed, of course, that scenarios are merely examples intended to provide concretely some of the many possibilities for which capabilities may be needed. Reasonable people may differ about whether CPGS would be a sensible option to use in any particular scenario, but forgoing the capability would mean not having the option even when it clearly would be needed.   hether a CPGS capability could actually be employed in the various scenarios would depend W on contextual details, such as the strategic environment and political circumstances and, of course, on whether the capabilities ascribed to the CPGS options are successfully achieved and supported by enablers such as described later in this chapter and in Chapter 4.  Many aspects of the event are described in Richard A. Clarke, 2004, Against All Enemies, Free Press, New York, Ch. 8. These include the early intelligence, days of preparation and decision making, the detection by Pakistan of some forward-deployed naval forces prior to the attack, and complicated politics. 

32 U.S. Conventional Prompt Global Strike Hussein at the Iraqi presidential compound at Dora Farms. Aircraft and cruise missiles already in the region were reassigned to strike at the reported site, but Saddam was not there. These historical instances illustrate that execution time can be a critical variable. 2. WMD shipment. A second class of scenarios is illustrated by the striking of a transshipment of one or more weapons of mass destruction (WMD), perhaps by truck or ship. Experience tells us that intelligence may exist about when a ship- ment is planned or may be en route, or where loading, unloading, or temporary stops may occur. Details may be lacking until late—perhaps when those doing the transporting stop for rest or maintenance, or when delays occur at a port, bridge, or border, including stops associated with routine inspections. In some cases, it might be possible for local police or military forces to make an intercept; in other cases, they might not be available to do so, or political considerations might pre- clude such action. Similarly, political factors might preclude the use of CPGS, as might the risk of collateral damage (caused, for example, by the dissemination of radioactive or noxious materials at the target). In other cases, a prompt strike with U.S. assets might be necessary and appropriate. One such scenario was sketched by former Secretaries of Defense Harold Brown and James Schlesinger in an article supporting CPGS capability. 3. Immediate response or preemption of imminent attack. A third class of sce- narios is illustrated by imagining that the United States, U.S. forces, or allies are about to be (or have been) attacked and that an immediate response is needed to prevent dire (or additional dire) consequences. Possibilities include conventional or nuclear missile attacks on U.S. cities, on U.S. forces or other military assets, or on U.S. allies. When such scenarios are examined in operational detail, the importance of prompt strike becomes evident: a response time of less than 1 hour might be essential to avert great losses (e.g., loss of numerous satellites crucial to U.S. command and control). In such cases, the CPGS might be the leading edge of a much larger military campaign. That is, the use of CPGS would not have to be large or decisive in itself. It could be very important despite being small. History is again useful. The very earliest part of the military campaign against Iraq in 1991 was a small, specialized, and focused attack on Iraqi air defenses. More gener- ally, military campaigns often begin with relatively small attacks on particular military targets that have leverage—in defeating or disrupting the adversary’s air defense; command, control, and communications (C3); or most-feared weapons. And for some of these, timing is critical. With today’s forces, such small leading- edge attacks might be conducted by Special Operations Forces (SOF) or other   A sober reading of history also reminds us how frequently human intelligence is wrong.   arold Brown H and James Schlesinger. 2006. “A Missile Strike Option We Need,” Washington Post, May 22. As an example of how complex a decision to use CPGS could be, consider that an “easy” strike on some platform carrying WMD might not be possible for fear of releasing toxic chemicals or radiation. 

MILITARY ISSUES 33 forward-deployed assets. In the future, such attacks might be accomplished with prompt global strike assets—with less need for forward basing and less concern about failure due to long flight times or detection. Is 1-Hour Capability Affordable? Having established that using a 1-hour criterion for promptness makes sense from the viewpoint of feasibility and that credible cases can be envisioned for which it would be valuable, the remaining issue is cost (and related trade-offs). Without elaboration here, since options on the matter are described later in this chapter and in Chapter 4, it can be stated that achieving 1-hour capability is rela- tively inexpensive (in DOD terms), although it could be quite expensive if the less-expensive CPGS options are ruled out for one reason or another. Conclusions on Definitions That Make Sense In summary, the committee concluded that defining conventional prompt global strike should not be too stringent with respect to the “global” criterion, but that the 1-hour criterion in defining “prompt” was sensible. That said, it could imagine systems (as discussed later) that might not quite make the criterion of promptness but that would be close enough so that they should be considered among the options treated. Attributes and Test Cases for Comparing Options Attributes Having discussed execution time and target classes, let us next consider the longer list of factors important to CPGS capability, displayed in Table 2-1. The first three have already been discussed (the second is a subset of the first); the others have not. Test Cases for Operational Scenarios The previous section and Table 2-1 outline a way to compare options tech- nically, but a more “operational” comparison is also needed, one more closely related to military utility in actual missions. One way to do this involves construct- ing a spanning set of scenarios construed as test cases. A spanning set needs to stress the alternative systems with respect to timeliness, target class, geographic depth, adversary air defenses, and the need to search and find targets at the time that weapons arrive. Drawing on the three scenario classes described earlier but thinking about the various operational issues to be considered, the committee constructed a set of six 

34 U.S. Conventional Prompt Global Strike TABLE 2-1  Variables Important to Conventional Prompt Global Strike Capability Feature Meaning Execution time Time from the order to execute until effects are achieved (assuming no contingent launch of aircraft or missiles) Final positioning and planning Time from the order to execute until systems are located and time supported properly and mission planning is accomplished. May be a part of execution time. Relevant prompt global strike Target classes (e.g., soft point targets, hard point targets) targets Lethality of weapons The probability of achieving the target damage sought, assuming successful delivery Ability to attack moving targets Ability to attack targets that are on the move when attacked Volume of fire The number of weapons available for use in a given strike Controllability Safety and security with respect to the weapons and their employment Geographic coverage The targets that can be reached without repositioning, e.g., without substantial sailing time or rebasing of bombers Risk of operational side effects The likelihood or potential for negative effects on, e.g., nuclear deterrent or Special Operations Forces operations At-the-time strategic factors Need or non-need for overflight rights, allied cooperation, or forward basing Availability Earliest initial operational capability Development risk The likelihood of serious development failures or slippages; a function of the technical readiness level of components, full-system testing, industrial base, and organizational competence Confidence in high reliability Assuming “successful development,” how likely would the system be to have high reliabilities (e.g., 0.95 rather than 0.6)? Evolutionary potential Value of the option in laying the technical and operational groundwork for subsequent, more advanced systems test cases as a reasonably good (but not exhaustive) spanning set. All are variants of the three scenario classes mentioned above, but they have been reformulated to focus on operational issues. They can be summarized as follows: 1a.  Immediate response to threat (soft targets, near-surface targets, moder- ate air defenses); 1b.  Immediate initial response to threat (soft targets, deeply buried targets, advanced air defenses); 

MILITARY ISSUES 35 2.   Attack of deeply buried WMD facility (hard, deeply buried targets, advanced air defenses); 3a.  Intercept of terrorism-related WMD transshipment (soft targets, near- surface targets, moderate or no air defenses, mobile targets); 3b.  Attack of terrorist leadership (soft targets, possibly under ground, and possibly moving; moderate air defenses); and 4.  Attack of key nodes as leading edge of military campaign. This set of test cases (scenarios) stresses the capabilities of candidate systems in different ways and, by and large, highlights the strengths and weaknesses of the alternatives. The quality of the testing, of course, depends on numerous details such as the quality of air defenses imputed to the adversary. The test cases should be stressful, but reasonable. A REPRESENTATIVE SET OF OPTIONS FOR CPGS Seven Options Analyzed The committee analyzed seven of the very large number of possible CPGS options, informed by results of the DOD’s ongoing analysis of alternatives (AoA) and the committee’s independent thinking. These options were as follows: 1. Existing systems: A combination of tactical aircraft, cruise missiles, and long-range stealthy bombers, supported as necessary with tankers; assets for com- mand, control, communications, computers, intelligence, surveillance, and recon- naissance (C4ISR); combat search and rescue (CSAR); and suppression of enemy air defenses. Some of these systems have very high accuracy and large payloads and, if pre-positioned in areas where targets are likely to emerge, have relatively rapid response times—but almost always measured in a few hours, not less. The exceptions are not a good basis for planning (see footnote 2 in this chapter). 2. Conventional Trident Modification (CTM): The option proposed in the President’s budget would use existing Trident missiles on nuclear-powered ballistic missile submarines (SSBNs). The intent is to have, on each of the 12 deployed SSBNs, 2 of the submarine’s 24 missiles armed with conventional rather than nuclear warheads. In its initial version, the CTM would have four kinetic energy projectile (KEP) warheads per missile, in a normal Trident reentry body augmented with an inertial navigator, Global Positioning System (GPS) receiver, and a modest maneuvering capability to strike precisely at GPS   A 2005 National Research Council report entitled Effects of Nuclear Earth-Penetrator and Other Weapons concluded, among other things, that many strategic hard and deeply buried targets can only be attacked directly with nuclear weapons. See National Research Council, 2005, Effects of Nuclear Earth-Penetrator and Other Weapons, The National Academies Press, Washington, D.C. 

36 U.S. Conventional Prompt Global Strike locations on the ground. The accuracy required is quite high, and testing to confirm that it has been achieved is essential. Lethality can be achieved against soft, relatively small-area targets with diameters up to about 10 meters (more if multiple warheads are appropriately targeted across an area), and can be significant against some point structural targets, as discussed in Chapter 4. The lethality of warheads would evolve over time (e.g., with a bent-nose warhead, as described in Chapter 4, which would improve effectiveness against some terrain-protected targets). 3. CTM-2: An option developed in the committee’s activities, this would remove the third stage of the Trident missile, thereby increasing payload capacity and conventional-payload options, while still achieving 4,000 nautical mile (nmi) ranges. Developing the CTM-2 would require relatively little modification of the existing missile, but it would require a few additional flight-tests to validate the modified guidance and control software. The base configuration would be as with the CTM—each SSBN would have two or more CTM-2 missiles. An initial ver- sion of the CTM-2 would use the CTM’s KEP warheads or the large penetrator reentry vehicles (RVs) that are more effective against hard or buried targets. Even the initial version could exploit bent-nose technology, as described in Chapter 4. Later versions could include ballistically delivered unmanned aerial vehicles (UAVs) with intelligence, surveillance, and reconnaissance (ISR) packages and weapons to reacquire and attack mobile targets. 4. Submarine-Launched Global Strike Missile (SLGSM): Conceived by the Navy as a potential mid-term system following up on CTM experience, the SLGSM would be launched primarily from existing nuclear-powered guided missile submarines (SSGNs) but could also be launched from SSBNs to extend coverage; it would have intermediate range and a single RV payload larger than the total payload of the CTM (it could also carry CTM-like payloads, of course). Because the SSGNs have a variety of missions, there would be some operational side effects related to the use of Special Operations Forces. 5. Boost-glide missile (initial version, CSM-1): The Air Force has proposed the Conventional Strike Missile (CSM) based on the proposed Minotaur launch vehicle described in Chapter 4. This would have boost-glide capability, extend- ing range and permitting large maneuvers to avoid unintended overflight. The Air Force proposed that its initial boost-glide missile have an 800-second glide in the atmosphere. The committee believes that to reduce technical risk and field a capa- bility quickly, the initial design should be limited to the delivery of a penetrator warhead or larger KEP warheads, rather than the munitions proposed for the next option (the “second version” of CSM). 6. Boost-glide missile (second version, CSM-2): The Air Force proposes a second, later variant of CSM with a 3,000-second glide in the atmosphere to increase its range and maneuverability. It would have more capability, more development risk, and a longer time to deployment than CSM-1. In the Air Force concept, both the initial and second versions would have the capability to slow 

MILITARY ISSUES 37 enough to dispense a wide variety of the Air Force’s arsenal of air-launched muni- tions (e.g., Small Diameter Bomb, Joint Direct Attack Munition [JDAM], and submunitions of various kinds, including the BLU-108 with Skeet warheads and possibly modules for ISR, battle damage assessment [BDA], and reattack). 7. Hypersonic cruise missiles: Hypersonic cruise missiles are being inves- tigated and, if developed, could be used for CPGS if forward deployed (e.g., on SSGNs) or launched from long-range aircraft. Such hypersonic cruise missiles would have only medium range but would have considerable capability for ter- minal-phase dispensing of smart munitions and ISR modules, and if slowed to subsonic speeds, could execute a search to reacquire and strike moving targets. Why Not Just Use the Minuteman? Although the committee considered all of the many options used in the DOD AoA and invented additional options and variants on its own, an obvious question for some readers may be, Why not just use the Minuteman missile? The committee investigated the option, but concluded that, although technically viable, the Minuteman III is not a realistic contender for reasons involving the complexity of issues described in Appendix I of this report. In short, the required renegotiation of the Strategic Arms Reduction Treaty, combined with “not-in-my- backyard” issues, presents substantial challenges to deploying intercontinental ballistic missiles (ICBMs) in locations such as Hawaii or Guam, particularly in the near term, as compared with other challenges associated with CTM deploy- ment. Furthermore, reducing the number of conventionally armed ICBMs to be deployed in Hawaii or Guam or using mobile units rather than silos will not offset these concerns. Like the Air Force, the committee gauged the pros and cons of land-based conventionally armed ballistic missile systems and decided against recommending the Minuteman as a near-term option. ANALYSIS Functional and Technical Analysis With the foregoing as background, the committee’s independent analysis of CPGS alternatives follows. Time and resource constraints precluded an in-depth study, but the analysis provides useful insights. Table 2-2 summarizes a qualitative technical comparison of the options, focusing only on military-technical issues. (The knotty “nuclear ambiguity” issue identified by some observers, including some in Congress, is discussed in Chapter 3.) Table 2-3 summarizes the committee’s rough estimates of earliest availability and total 20-year system costs. The estimates are informed by material from the DOD and from contractors and by some committee members’ long experience in capability development. 

38 TABLE 2-2  A Qualitative Technical Comparison of the Conventional Prompt Global Strike (CPGS) Options Reviewed by the Committee Investment Options CTM-2 Variant Boost-Glide Boost-Glide Hypersonic Existing (with Missile Missile Cruise Measures Systems CTM CTM-2 UAV)a SLGSM (CSM-1) (CSM-2) Missiles Execution time Positioning/final planning time Geographic coverage Defense penetration Lethality Ability to attack moving targets Volume of fire Assessment and reattack Controllability 

Ability to attack moving targets Volume of fire Assessment and reattack Controllability Impact on other missions Need for bases, overflight Earliest availability (initial operational capability) Development risk Confidence in high reliability Value for capability evolution A warning marker (top right corner of cell) indicates a result of averaging good and bad cases. Very Good Marginal/ Poor Very Poor Good Mixed NOTE: A black warning marker indicates a result of averaging good and bad cases, for example, cases with and without advanced air defenses. Scores for many rows assume fully successful development and political circumstances permitting CPGS; they do not consider countermeasures and counter countermeasures except where mentioned in text. aCTM-2 with unmanned aerial vehicle (UAV) is not among the seven CPGS alternatives reviewed by the committee; however, it is included in this table as a postulated variant of CTM-2 to indicate its potential value against more difficult mobile targets. 39 Table 2-2, editable 

40 U.S. Conventional Prompt Global Strike TABLE 2-3  Estimated Earliest Initial Operational Capabilities (IOCs) and Costs 20-Year Cost Cost to IOC (relative to CTM: (relative to CTM: Alternatives Earliest IOC billions of 2009 dollars) billions of 2009 dollars) Existing systems Available now Not Applicable Not Applicable CTM 2011 1 0.5 CTM-2 2013 3 1.5 CTM-2 (with UAV) 2016-2020 5 3.5 SLGSM 2014-2015 5-10 5 Boost-glide missile 2016-2020 10-20 5-15 (CSM-1) Boost-glide missile 2018-2024 10-25 5-20 (CSM-2) Hypersonic cruise 2020-2024 10-20 5-15 missiles NOTE: Actual IOCs for all but the CTM are likely to be later for many reasons, including delays in decision making, the time required to stand up program offices, and other factors. The costs shown are merely rough estimates to make distinctions. Actual costs are more likely to be higher than lower, but the committee believes that the ordering is about right. Acronyms are defined in Appendix A. In Table 2-2, the color coding indicates the committee’s assessment of options as “very good,” “good,” “marginal/mixed,” “poor,” and “very poor” (or equiva- lents, such as a very high development risk or late initial operational capability [IOC] being treated as “very poor”). It is essential that the reader recognize the ground rules for the assessment to avoid misunderstanding. The most important are discussed below. • In most rows of Table 2-2, the committee evaluates the options with the assumption of success; that is, the option is scored for the measure in question (e.g., execution time) based on the planned capability. However, in other rows (those near to the bottom), options are marked down because of high development risk, long development time, or questions about whether the systems would have high reliability. • The committee also evaluates the options on a relative basis, looking at what is being sought for the measure in question. For example, an execution time of 1 hour would rate as “very good” even though the committee might prefer zero time of flight. More subtle, a “very good” lethality score does not, for example, imply capability against large-area, hard and deeply buried target complexes about which there is no detailed information on vulnerabilities. Taking an example at the other end of the spectrum, a very poor score (such as for execution time) does not mean that the option would never be able to execute quickly, but rather that it could do so only in a very restrictive set of circumstances. 

MILITARY ISSUES 41 • Some evaluations are inherently ambiguous because they are an “average” across cases with markedly different results. Cells evaluated as “marginal/mixed” with warning markers in their top right corners indicate evaluations that could be either good or bad, depending on unspecified details, or cases on which there were mixed evaluations. It follows that assessments such those in Table 2-2, and in Table 2-4 on pages 48-49, should not be interpreted out of their analytical context. Most impor- tant, they should not be read to mean that any of the options would never have capability or that any option would always have capability. With these prefacing comments, the basis for the committee’s assessments can be described briefly as follows. 1.  Execution time. For reasons discussed earlier, a goal of 1 hour for execu- tion time was used as a reasonable basis for scoring. Existing systems (tactical aircraft, bombers, and cruise missiles) rate poorly because they could achieve such times only in very special cases (see footnote 2 in this chapter). Moreover, if the targets at issue were deep inside a large country, far from launch locations, execution times might be much longer (e.g., 10 to 20 hours, depending on launch point). Hypersonic cruise missiles would depend on forward-stationed forces, and boost-glide missiles such as the CSM-1 and CSM-2 are intended to have longer flight distances and flight times, which might well be adequate but could be short of the 1-hour goal. 2.  Positioning/final planning time. Even if forward stationed and poised, existing systems may not prove to have been stationed and poised in the right place for a strike and may require support by tanker aircraft and other enablers. Further, final mission planning can take considerable time, especially for working out paths of flight to avoid or defeat air defenses. This would more likely afflict existing systems or hypersonic cruise missiles than it would affect dedicated CPGS systems. These options, therefore, are marked down slightly because they depend on special circumstances. 3.  Geographic coverage. Most of the options will have the geographic coverage that the committee believes necessary. The exception for existing forces, SLGSM, and hypersonic cruise missiles is targets deep inside large countries. Hence they are scored down somewhat on this measure. This is an instance in which the committee has not required full global reach. Another factor in the time line, of course, has to do with “enabling” actions, discussed later in   the chapter. These involve gathering and assessing intelligence, establishing precise geolocations of targets, decision making, and transmission of orders. Every effort should be made to do whatever is possible to reduce these other elements of the time line, even though they are often not the limiting factors. 

42 U.S. Conventional Prompt Global Strike 4.  Defense penetration. Advanced air defenses are a threat to existing sys- tems and are likely to be purchased by states that are far less capable generally than a “peer competitor.” There will continue to be cases—in particular as stealth technology and countermeasures evolve—where defenses can be defeated, but in other cases they would severely affect the feasibility or risk of missions (e.g., the risk of having crew killed or captured). U.S. ballistic missiles are likely to have minimal penetration problems for many years (although countermeasures might be necessary). Thus, the CTM, CTM-2, SLGSM, and CSM-1 (initial version of the boost-glide missile) all merit “very good” scores. Evaluations of the other systems are difficult to make, and differences of opinion exist even among experts. Some studies suggest that, because of their unpredictable maneuvering, these systems should be able to penetrate advanced air defenses. Some experts on the committee were less sanguine because, if used with some payloads, CSM-2 (the second version of the boost-glide missile) and hypersonic cruise missiles must slow down substantially, either to dispense munitions, to conduct ISR activities, or to assess and reattack. That would increase their vulnerability to air defenses. This said, such payloads would arguably be most relevant to the attack of targets that would not be well defended (e.g., terrorist leaders). Because of such ambi- guities, disagreement, and case dependence, the committee rated the CSM-2 and hypersonic cruise missiles “marginal/mixed,” with the warning markers in Table 2-2 indicating ambiguity (i.e., the systems can be good or bad by this measure, depending on details of circumstance). 5.  Lethality. The baseline version of the CTM, assuming that it achieves its accuracy specifications, is expected to be highly lethal for some important targets, but there is a significant set of potential targets—mobile, hard, or exten- sive—against which it will have limited capability, not only compared with more ambitious CPGS concepts but compared with existing systems. This is due to the CTM’s small reentry bodies and—in the baseline concept—small number of weapons available per target, as well as to the nature of the warhead. The CTM’s lethality can be improved incrementally in ways that the DOD recognizes and in additional ways that the committee suggests (see the discussion later in this chapter), but the CTM is not credited with those improvements here. The other systems should have greater lethality against a range of targets, assuming neces- sary intelligence—and, in some cases, an ability to receive and use target loca- tion updates after launch. Some of the weapons systems would have a variety of loading options (e.g., penetrators, area weapons). No CPGS option is likely to be effective against all targets, even with good intelligence. For example, hard, deeply buried target complexes are very difficult to attack without knowing their special vulnerabilities. Thus, a “very good” score does not mean high lethality in all cases; it means only that a reasonable goal for CPGS weapons has been met. 6.  Ability to attack moving targets. Capability against moving targets would be minimal for all options unless they had the ability to detect and track such targets or to receive and use updated information from other platforms until very 

MILITARY ISSUES 43 late in their flight paths. Such capabilities are postulated for CTM-2 (with UAV), for CSM-2 (the second version of the boost-glide missile), and for the hypersonic cruise missiles, although achieving those capabilities entails high development risk and long development times. Further, the sufficiency of capability would be in doubt given the potential for adversary tactical countermeasures (e.g., pro- liferation of targets) and dependence on intelligence to narrow search areas for submunitions. 7.  Volume of fire. The number of weapons that might be employed in a CPGS mission is perhaps in the range of 10 or fewer for scenarios such as those involving terrorist leaders or WMD shipments and perhaps as many as 100 (which would require a CPGS deployment larger than those considered in this study) in scenarios employing CPGS as the leading edge of a larger military campaign. The CTM would have a limited volume of fire (although it could be increased by using more warheads per missile, at the expense of some range), so it is marked down somewhat.10 The other systems have sufficient volume of fire for the mis- sions on which the committee assessed capability, which might require tens, but not hundreds, of weapons.11 8.  Assessment and reattack. For some of the options, it is possible for the strike system itself to conduct a degree of assessment and/or a degree of BDA, which could be crucial in subsequent military decisions, including those about the need to reattack. Some of the options, particularly the CTM-2 (with UAV), CSM-2 (the second version of the boost-glide missile), and hypersonic cruise missile options, envision releasing sensors and communication devices as part of the strike; these have the potential to support real-time BDA and reattack of some targets as part of the strike itself, although achieving such capabilities is a formidable longer-term challenge. 9.  Controllability. It is important that CPGS systems be subject to very high levels of safety and security. It appears that the currently planned control mechanisms vary with the option. They would be quite stringent for the CTM 10  he T committee considered only limited deployments of CPGS systems. Large-scale deployments would raise very important issues, such as the appearance of a disarming first-strike capability, that have not been addressed. The committee recognized that the CTM proposal involves only two conven- tionally armed missiles per submarine, and did not analyze or discuss in detail the issues that would arise from the deployment or use of larger deployments. 11  t is sometimes suggested that CPGS systems could have a role along with nuclear weapons in I planned options for strategic attacks, by using very long range, highly accurate conventional strikes in place of nuclear weapons to hit suitably soft and/or small targets that are now assigned to nuclear weapons. This concept of CPGS raises different issues from those posed by either the “niche” capa- bilities or the “leading-edge” capabilities discussed here. Among many other differences, the numbers required would almost certainly have to be quite large, if the stated purpose of achieving Single Integrated Operational Plan (SIOP)-like effects while using markedly fewer nuclear weapons were to be achieved. (The SIOP is a classified blueprint that specifies how nuclear weapons of the United States would be used in the event of nuclear attacks.) 

44 U.S. Conventional Prompt Global Strike and CTM-2,12 but perhaps less so for the others, especially the SLGSM launched from SSGNs. One issue for the SLGSM is whether a weapon could physically be launched without the conventional-weapon equivalent of an emergency action message. If the answer is no, that is, if the same protections would be built in as for the CTM, then the SLGSM’s score by this measure would be “very good.” 10.  Impact on other missions. A significant question raised by the Con- gress is whether the adoption of a given CPGS option would compromise other missions. The CTM program and the committee’s baseline configuration for the CTM-2 involve a mixed load of nuclear and conventional missiles. It has been argued that this would create operational problems and also lead to new operating procedures that might degrade somewhat the survivability and target coverage of the SSBN force. The DOD has studied such matters, and the membership of the committee included individuals with personal command experience in such mat- ters. The committee concluded that these adverse consequences would be modest and quite manageable. They would be larger if the CTM or CTM-2 were deployed in a “pure-load” configuration (i.e., perhaps two Trident submarines, each car- rying 24 CTM or CTM-2 missiles and no nuclear weapons). Such an approach might reduce the ambiguity concern, but it would have a larger impact on nuclear operations because of the reduced number of nuclear-armed SSBNs (unless the size of the fleet were increased, which would be expensive). It is the committee’s judgment that the number of available nuclear weapons could be maintained by increasing the number of warheads on those missiles with nuclear weapons, but there would still be concern about having concentrated the on-alert nuclear sub- marine-launched ballistic missiles (SLBMs) on two fewer on-patrol submarines. The biggest operational impact of CPGS would be associated with the SSGN- based SLGSM option. The primary impact would be due to the SSGN’s having important SOF-related missions,13 which would tend to call for different opera- tional deployments and operating procedures than would the CPGS mission. The SSGN crews would have to train for the different missions, and choices would need to be made, perhaps frequently, about relative priorities.14 11.  Need for bases, overflight. One of the primary features of the CPGS concept is the capability to permit an immediate (less than 1 hour) strike. Although the United States has forward bases and arrangements with local states permitting or tolerating overflight rights, and although unilateral overflights can be made 12  ronically, this level of security and safety, including the use of emergency action messages, I is regarded by some as increasing the so-called nuclear ambiguity problems addressed later in the report. 13  or example, SSGNs may be charged with the transport of Special Operations Forces, a mission F that may be compromised if the focus is instead on CPGS readiness. 14  Precisely which SSGN missions would be emphasized at a given time is unclear. A Congressional Budget Office study discussed the range of potential missions that have been mentioned, showing the potential for conflicts (Congressional Budget Office, 2002, Increasing the Mission Capability of the Attack Submarine Force, Washington, D.C., March, pp. 16ff.). 

MILITARY ISSUES 45 when necessary in any case, these considerations are weighty and may reduce the U.S. ability to act quickly and unilaterally.15 12.­­ Earliest availability (IOC). It is notoriously difficult to estimate the time   at which a weapons system would have initial operational capability (IOC), or final operational capability (FOC). That difficulty increases with the ambitious- ness of the program at issue. Program offices and contractors have incentives to be optimistic, engineers think in terms of what could be done. Others worry about what is likely to be done, given the probability of delays associated with decision making in both the DOD and the Congress, funding slippages, the time required to set up or reinvigorate development organizations and commands, and the record in recent decades of IOCs coming later than initially advertised. The committee saw contractor briefings suggesting that almost all of the CPGS options could be fielded within about 5 years from go-ahead (and at remarkably low costs). However, after reviewing the materials provided by the program offices of the Navy and Air Force, the Office of the Secretary of Defense (OSD) (Acquisition, Technology and Logistics), and the U.S. Strategic Com- mand (STRATCOM), as well as the analysis of alternatives being conducted for the DOD with the Air Force as executive agent, the committee—drawing also on the judgment of its own members with relevant experience, expertise, and skepticism—estimated the IOCs as shown in Table 2-3. These are earliest plausible IOCs. The CTM’s IOC is highly credible (subject primarily to early authorization) because it is a very incremental effort within a mature organization with a long track record of delivering; the CTM-2’s earliest IOC is shown as a year or two later because it seemed that any change of concept would involve some delay, and because some testing of the two-stage Trident with a CTM payload would be needed. The IOC shown for the SLGSM is also credible, since the Navy has laid much of the technical groundwork, would again be pursuing incremental development within an existing organization and has been consistently conserva- tive in its estimates. Initially, the committee believed that the boost-glide missiles or hypersonic cruise-missile options were likely to be long term in nature, more like 2020 than earlier. It is possible that research and development (R&D) tests that are already programmed will prove successful and reduce some of the more worrisome risks—for example, that of the ability of materials to tolerate long hypersonic periods of flight. It is also possible that decisions could then be made with unusual swiftness to authorize full programs. Thus, it would then seem pos- sible for IOCs to be achieved as early as 2015, although not with the same level of performance reliability and stability as would be possible for the CTM, CTM-2, and SLGSM options. Accordingly, the committee’s estimate of the earliest IOC of each of these boost-glide missile and hypersonic cruise-missile systems is 15  This criterion should not be misinterpreted. Forward basing and other access arrangements are desirable and important for many strategic reasons that would not be affected by the existence of CPGS capability. 

46 U.S. Conventional Prompt Global Strike expressed as a range. In summary, the committee concludes that there are only two relatively early options (both based on Trident missiles and submarines), one highly credible mid-term option, and two (more, if one counts variants) interesting options with mid-to-long-term potential. 13.  Development risk. The CTM and CTM-2 options clearly have the low- est risk and, based on empirical knowledge and the modest level of technology extrapolation, the committee judges the risk to be low on a relative basis—assum- ing, however, completion of the careful testing program that is planned. The successive options involve increasingly more risk. The committee’s assessments reflect systematic consideration of how much of an extension of current technol- ogy is involved relative to prior capabilities, technology readiness levels (TRLs) for component technologies, and other factors such as maturity and past success of industrial and government organizations. 14.  Confidence in high reliability. In principle, any of the systems under consideration could be designed to achieve high reliability. However, the com- mittee noted that strategic systems have been designed for high reliability (more than 90 percent reliability) routinely for decades, whereas tactical systems have widely varied reliabilities—in part because it is difficult and expensive to raise the reliabilities of air-breathing systems to high levels. For this reason, the committee expressed doubts about the confidence that would be achieved in the reliability of CSM-2 or the hypersonic cruise-missile options, at least at the time of IOC. Fur- ther, the committee reasoned that the UAV-carrying variant of the CTM-2 would be more likely to have early difficulties, even if largely successful. And, finally, there are enough differences between the SLGSM and CSM-1 on the one hand and existing systems on the other that difficulties might be expected. This kind of qualitative reasoning was the basis for the evaluations shown. Even if developments proceed well, the committee believed that the reliabili- ties achieved in the timescales noted might prove unacceptably low for the CSM-2 and hypersonic cruise-missile options. Better results would then be achievable in time. It may be that reliabilities would be high from the outset, at least for the boost-glide missile (initial version), but risks for the CSM-2 and hypersonic cruise-missile options would have to be judged to be considerable. Again it is noted, however, that the issues here are not fundamental; higher reliabilities could be required and achieved with sufficient effort. 15.  Value for capability evolution. A measure that the committee believed to be important was whether a given option had growth potential or would con- tribute materially to the development of follow-on systems. Particular follow-on systems might or might not be desirable and, as discussed in Chapter 3, there are profound issues involved with such development and deployment decisions. Nonetheless, from the pragmatic perspective of investing in system development, evolutionary potential is important. The assessments presented bear explanation. The CTM itself would provide not only an important early capability but also an important basis for further development, either to the CTM-2 or to something 

MILITARY ISSUES 47 like the SLGSM. It would provide considerable technical and operational data and experience relevant to the boost-glide option. The CTM-2 would have even more evolutionary potential because it would have a larger payload capacity. The SLGSM, as described, has more limited evolution potential because the missile has only intermediate range and limited capacity for growth to larger payloads. The boost-glide missile and hypersonic cruise-missile options would have plenty of room for further evolution, although concerns about air defense are significant, and some committee members are skeptical about the feasibility—even in the long run—of being able to use such systems effectively against noncooperative moving targets. Effectiveness Analysis The committee conducted a rough analysis of the effectiveness of the planned capabilities of various CPGS options using the spanning set of scenarios described earlier. This analysis, which is based on the four major operational scenarios covered by the test cases, is summarized in Table 2-4. Cells in this table with a warning marker in the top right corner have been evaluated as a compromise between better and worse cases. That is, depending on details of the scenario, the system might be very effective or ineffective. The factors include the presence of air defenses, whether targets are moving, and whether the payload involves penetrating weapons or dispensed weapons. Discussion of Evaluation in Test Cases The test cases are formulated specifically for the purpose of evaluating the potential of systems for CPGS in the period between 5 and 15 years from now, not for global strike generally, and not for today. Existing systems do not do well in the committee’s evaluations because of not being “prompt” enough and because of worries about emerging air defenses and/or inability to attack moving targets. This is so even though there are cir- cumstances where existing systems could be used effectively, as they have in the past. The problem with existing forward-deployed strike forces is that they are generally not close enough to execute a strike within 1 or 2 hours—even within a theater of operations. It takes time and diverts many resources to generate forces and supporting functions for a strike. Tanking must be provided and coordinated with strike tactical aircraft, and often overflight permission or defense penetration must be dealt with. Mission planning can be time-consuming when air defenses are a problem. For these reasons, these forces get low marks for execution time as it affects the scenarios in this assessment. Finally, while the development and operating costs and risks are minimal, given that they already exist and are deployed forward anyway, relocating such forces entails a large expense because of the large logistics tail that supports them. 

48 TABLE 2-4 Evaluation of the Conventional Prompt Global Strike (CPGS) Options in a Set of Test Cases Measures Attack Weak Points Attack Terrorists Strike C3 Nodes in Respond Fast to of Hardened WMD Fast (Leaders or Leading-Edge Investment Options Attack or Threat Facilitya WMD) Attack Existing systems CTM CTM-2 CTM-2 (with UAV) SLGSM Boost-glide missile (CSM-1) 

CTM-2 CTM-2 (with UAV) SLGSM Boost-glide missile (CSM-1) Boost-glide missile (CSM-2) Hypersonic cruise missiles A warning marker (top right corner of cell) indicates a result of averaging good and bad cases. Very Good Marginal/ Poor Very Poor Good Mixed NOTE: Evaluations assume successful development and political circumstances allowing use of prompt global strike. They do not con- sider countermeasures or counter countermeasures. Evaluations also assume “good cases.” For example, none of the weapons would have significant capability against large, complex, hard and buried complexes—unless the complexes had special vulnerabilities that could be exploited. Similarly, moving targets would only sometimes be targetable. Acronyms are defined in Appendix A. aAn effective CPGS capability against hard and deeply buried targets is restricted to special cases. In this column, the selected cases as- sume advanced intelligence about the targets and their vulnerable accoutrements, such as their entrances, and the inability of the facilities to function effectively if the accoutrements are disabled or destroyed. Furthermore, it is important to note that a 2005 report of the National Research Council entitled Effects of Nuclear Earth-PenetratorTable 2-4, editable and Other Weapons (The National Academies Press, Washington, D.C.), concluded, among other things, that “[m]any of the more strategic hard and deeply buried targets are beyond the reach of conventional explosive penetrating weapons and can be held at risk of destruction only with nuclear weapons” (p. 1). 49 

50 U.S. Conventional Prompt Global Strike The CTM succeeds in the test cases shown in Table 2-4 (columns one and four) because of its promptness, but it has no ability to attack hard facilities, only limited capability against terrain-protected targets, and no ability against moving targets.16 The score for the “Attack Terrorists Fast (Leaders or WMD)” test case (third column in Table 2-4) is mixed because the targets might or might not be moving. In the latter case, the CTM and CTM-2 would be capable. Given a UAV, the CTM-2 could have capability against moving targets as well. The SLGSM and CSM-1 have no moving-target capability and so are rated the same as CTM and CTM-2. The CSM-2 (with UAV) and hypersonic cruise missiles would have moving- target capability, but, depending on load and possible maneuvers, might or might not be able to cope with advanced air defenses. Such defenses would probably not apply for the “Attack Terrorists Fast (Leaders or WMD)” test case, however. For the other cases, the table shows results as “good,” but “marginal/mixed.” These systems should do relatively well if loaded with payloads not requiring them to slow up in the terminal phase. With payloads requiring the slow-up, it is unclear whether they would be able to deal well with advanced air defenses. It is a matter of speculative disagreement. On balance, this “Attack Terrorists Fast (Leaders or WMD)” test case seemed to merit a score of “good.” By and large, all of the planned options would achieve significant capability in most of the test case scenarios. The moving-target cases pose the most serious challenge. It is imperative to understand, however, that the evaluations are for “good cases,” such as when a deeply buried target has a special vulnerability, or when moving targets are out in the open where collateral damage is not a concern. None of the options would have capability in all versions of any of the scenarios, but the analysis indicates that the “good cases” are plausible enough to plan for. One of the factors complicating this analysis is that effectiveness depends on weapons loading, and most of the options have multiple potential loadings. The DOD will want more explicit analysis regarding the ability to adjust loads (and concepts of operations) based on strategic warning. For example, if a plausible threat to nuclear SSBNs arose, SSBNs could return to maximally secure opera- tions; or more likely, if the need to attack hardened sites became evident, unitary penetrator weapons might be favored over KEPs. How long would it take for reloading? Some weapon systems could have a mix of weapon types at a given time; others could not. 16  he committee evaluated the CTM as it was described to the committee, but noted that the CTM T could be given more capability against terrain-protected targets relatively easily and that eight, rather than four, RVs could be carried on a given missile, thereby increasing the volume of fire and capabil- ity against area targets or targets for which geospatial location information was slightly unreliable. Flechette density could also be increased, with more numerous, smaller, flechettes. 

MILITARY ISSUES 51 Enablers of Conventional Prompt Global Strike So far this chapter has focused on the potential effectiveness of the CPGS platforms and weapons. It has pointed out that in many and perhaps most of the plausible circumstances of CPGS employment, there would be warning time per- mitting intelligence collection and synthesis, precise targeting, preliminary deci- sion making, and other preparations. In such cases, the measures discussed (e.g., execution time, lethality) would be especially important. In some cases, however, many of the “enabling activities” would also need to be done quickly—if not in minutes, then in hours or a few days, rather than weeks and months. Whether or not additional time was available for them, the enabling activities would be criti- cal, not merely desirable. The material that follows touches on such enablers, including the challenge of ensuring that aimpoints are properly geolocated. Challenges for Enablers The use of long-range missiles to deliver conventional weapons accurately enough to damage targets requires information that is significantly more difficult to provide than that needed for nuclear weapons or for conventional weapons delivered by aircraft or short-range missiles. The primary issues relate to the following: (1) command and control (C2) that reserves decisions to the National Command Authority, while delivering information to the weapon system quickly for a short overall execution time; (2) the provision of the information necessary for accurate weapon delivery to a specified aimpoint; (3) the accurate location of aimpoints; and (4) target detection. The following paragraphs discuss these issues in order. At the outset it is noted that the timely information available for early versions of CPGS, such as CTM, will be sufficient for many important targets of interest. However, it will be some years before the information will be sufficiently timely for a broader set of targets, especially those that are moving while being attacked. That is, one should assume considerable evolution over time and consider the possibility of follow- ing a dual track; deploy quickly a system able to expand the present capability and use existing technology (including technology for enablers) while pursuing work toward longer-term capabilities as technology advances (and, possibly, new missions are identified). Command and Control The command-and-control problem for the CTM is greatly simplified by adapting modestly the existing C2 system used for the nuclear-armed Tridents— the system developed for controlling the major strategic nuclear system of the nation. Its CTM variant17 would be both effective and cost-effective. Such is not 17  he T proposed program would add a number of hardware and software provisions to prevent 

52 U.S. Conventional Prompt Global Strike necessarily the case for alternative future systems, which are being conceived as strictly conventional, in part to get away from the concerns expressed by some observers about mixed loads of weapons (i.e., mixes of nuclear and conventional). Such future systems, as currently conceived, would not be tied into the nation’s C2 system for strategic (albeit non-nuclear) weapons, even though decisions about the use of such strategic weapons will almost surely be made at the highest level of the government. It is unclear to the committee whether physical control of the weapons will be strong enough, and whether the mechanisms will exist for an efficient matching of targets and weapons—something routinely considered in the existing nuclear C2 system. The committee believes that any CPGS option should be regarded as “strategic” and demanding of extremely high safeguards. Accuracy The accuracy required for CPGS is on the order of meters in each of three dimensions (two dimensions on the surface of the ground and one “vertical” dimension relating to target elevation and fusing altitude). Such results have been achieved with short-range systems after several iterations of guidance- system details (in Chapter 4, see the subsection entitled “Guidance, Navigation, and Control Accuracy Issues”), but the CTM or other future systems will need to achieve excellent accuracy from the outset. Even with results from testing, ensuring that a single or a handful of shots will achieve such accuracy every time is very challenging. Several studies have shown that bias errors will be trouble- some in some cases for the CPGS systems.18 Given the limited payloads and small radius of effects for conventional weapons, there is little room for error in any of the three dimensions. These CPGS systems will require GPS updates to correct inertial guidance systems toward the end of flight and perhaps will need to include additional systems to correct for bias errors (a capability not available for early systems). Also, the requirement to protect the weapon itself from heat and other atmospheric effects implies correct compensation for aerodynamic effects over significant time periods, during which velocities and orientations are changing significantly. Development and full-scale, system-level testing are essential. That testing is one of the highly attractive features of the proposed CTM program and would be important whether or not the CTM were deployed. If CTM research, launch of a nuclear weapon rather than a conventional weapon when a conventional-weapon attack was intended. Safety, in this case, would rely not only on rigorous procedures but also on well-tested hardware and software safeguards. The committee found this aspect of the CTM’s design to be es- pecially attractive. 18  Accuracies are usually quoted in circular error probable (CEP) terms, with CEP measured around the intended impact point. Bias errors are another matter: the intended impact point may be displaced significantly from where the actual target is located. One contributor to that error is target location error (TLE), and it is not a function of the guidance system or the number of times that the missile has been flight-tested. 

MILITARY ISSUES 53 development, testing, and evaluation (RDT&E) are terminated, other systems will start from a much more primitive technological base. Aimpoint Location Also challenging is determining the location of the target to be struck. CTM and its early evolutions will be limited to striking locations known before launch—locations that contain the right targets and have reliably established coordinates. Targets will need to be stationary for at least 1 hour to be struck effec- tively, unless their arrivals at fixed locations can be accurately predicted. Future versions of the weapons might allow an in-flight update of the target location, but the targets would still need to be stationary for the times between last update and impact, which might be tens of minutes. Any error in the actual location of the target (target location error, or TLE), including bias errors, needs to be significantly smaller than the weapon’s range of effects, which means that TLE needs again to be on the order of a few meters. While such accuracy is difficult in the two dimensions of ground position, it is even more difficult currently for the vertical dimension. That situation is improv- ing, as discussed below. Horizontal accuracy can be improved significantly by measuring position relative to a known “fiduciary point” recorded by the National Geospatial-Intel- ligence Agency (NGA). NGA produces an extensive Digital Point Positional Data Base (DPPDB) of reference photos with embedded and accurately determined reference points, or fiduciary points. The DPPDB enables mission planners to derive in minutes accurate geographic coordinates for a visually observable point—for example, from a recent photo taken in the field. The DPPDB today covers significant areas in known hot spots around the world. In the event that a target emerges in an area of the world not covered by the DPPDB, the process of reducing TLE to an acceptable level can take days or even weeks. In cases where the TLE is only somewhat degraded, CTM with KEP warheads could still be effective by pattern-targeting its RVs over the target to increase the area over which lethal effects are spread.19 Target Detection and Localization In addition to the problems of location and control described above, there remains the challenge of finding a target in the first place, especially in the case of a movable, but not continuously moving, target at rest. If U.S. forces are deployed in the area and maintain control of the airspace, a high-altitude system such as 19  Pattern-targeting” as used here means that the individual shots would be directed at slightly “ different aimpoints in a pattern around the nominal aimpoint so as to increase the probability of a successful impact despite small residual bias errors in the target’s actual location. 

54 U.S. Conventional Prompt Global Strike Global Hawk could detect and locate a target with synthetic aperture radar or light imaging—assuming suitable fiduciary points. However, where satellites are needed to detect the target, the detection will be episodic at best. And sometimes it will be necessary to rely on human intelligence and to translate information like “The ship is moored at Pier 9” into coordinates. Today, with the war in Iraq requiring maximum support by scarce ISR resources, the competition for satel- lite resources is severe, but it is difficult even in more normal times. There are significant limits on how quickly satellite tasking can be adjusted to accommodate even the highest intelligence priorities. Fortunately, when there is activity some- where in the world that might call for use of a CPGS weapon, there is likely to be heightened interest for other reasons as well, so that the satellite systems will be concentrating their coverage on the problem area. The National Reconnaissance Office (NRO) developed plans and programs in the 1990s to address the revisit problem by increasing the area of Earth observed per day by a factor of about 100. While there have been program cancellations and delays, about a factor-of-10 improvement should have been effected by the time the CTM is deployed. The planned Air Force Space Based Radar Program, which is in the initial stages of implementation, will provide relatively persistent coverage of chosen points on Earth, with maximum gaps between available obser- vation times measured in tens of minutes.20 This revisit time does not guarantee the ability to track a target with certainty to see where it stops, but it is effective where congestion is not too high, such as in areas where potential CTM targets would most likely exist. If this program is deployed, by 2020 its ability to find targets for CTM and its successors will change from being episodic to being relatively reli- able. In addition, these new systems (the NRO programs and Space Based Radar Program) will allow acceptable TLE determination after a few observations—after approximately 30 minutes with systems of the Space Based Radar Program and within a day or less for those of the new NRO programs, without using fiduciary points, if this capability is built into these systems. Only when sufficient work has been accomplished in advance to provide very accurate fiduciary points near a target will CTM and its successors be provided with information about fixed aimpoints with a TLE small enough to expect that the weapon will achieve the programmed damage. A patterned attack with multiple RVs could mitigate these problems. Adding more RVs to the CTM, as discussed elsewhere in this chapter, would increase the ability to do such patterned attacks. For fixed facilities, this is straightforward. For other potential target locations that have a time-dependent value, such as a pier that is a valuable target when it has WMD cargo ready to load but not when it is empty, the detection of the 20  Congressional funding for development of the Space Based Radar Program has been limited over the past few years. For an overview of the program, see General Accounting Office, 2004, Defense Acquisitions: Space-Based Radar Effort Needs Additional Knowledge Before Starting Development, GAO-04-759, Washington, D.C. 

MILITARY ISSUES 55 increased value will probably be provided by satellites or other sources episodi- cally. Because CTM and other envisioned CPGS systems will rely on ballistic or high-altitude delivery of the weapon, terrain masking and other protection capabilities will be relatively ineffective, and additional data concerning the surrounding area will most likely not be needed. However, when payloads must be delivered using maneuvering RVs with limited corner-turning capability, the requirement for information to support flight planning will increase. Such data should still be available from the NRO systems and would be available from the space-based radar when the payloads are delivered by canister into what is in effect an atmospheric-flight terminal engagement. The requirement for accurate position location is then reduced significantly, as is the constraint on effectiveness on mobile targets, because that engagement can use onboard sensors to control terminal maneuvers—for example, GPS plus fine imagery to move the aimpoint by a few meters. Because the initial CTM system will have so few system tests before deploy- ment, the tolerance for error in the enabling systems will be small. It will be very important to have tests by the NGA using precise measurement of errors in the location of known fiduciary points to detect and overcome bias errors. In addition, NGA will need to determine accurately and quickly fiduciary points in the vicinity of potential targets to use when a satellite happens to locate a target of interest. Later versions of CPGS could use a more robust system of enablers, with world-networked capabilities to share information being deployed, and signifi- cantly improved satellite reconnaissance capability to find targets and track them. Later CPGS versions themselves will have better terminal systems and will also require less external information in order to be effective. Exactly how those capa- bilities will be combined is unknown at this time, but the constraints on the CTM itself are well defined and subject to analysis, simulation, and, most importantly, testing of the enabling systems. Ensuring Safety and the Absence of Errors A strategic system such as CPGS must be designed with extremely high lev- els of protection to ensure safety and the absence of mistakes. As the world was reminded recently when nuclear-armed missiles were accidentally loaded onto a B-52, transported to another air base, and essentially left unattended for many hours, mistakes can happen—even with the nuclear weapons to which the United States has applied special precautions for decades.21 21  n I response to the incident of unauthorized movement of nuclear warheads from Minot Air Force Base, North Dakota, to Barksdale Air Force Base, Louisiana, Secretary of Defense Robert Gates authorized an independent investigation of the incident resulting in the following report: Defense Science Board, 2008, Report on the Unauthorized Movement of Nuclear Weapons, Permanent Task Force on Nuclear Weapons Surety, Washington, D.C. For additional reading, see Joby Warrick and Walter Pincus, 2007, “Missteps in the Bunker,” Washington Post, September 23. 

56 U.S. Conventional Prompt Global Strike The proposed CTM program raises at least the possibility of an accidental launch of a nuclear weapon instead of the intended launch of a conventional weapon because (1) both kinds of weapons would be carried on the same subma- rine platform and (2) prompt global strikes may often allow little time for second checks. General Considerations The committee discussed at some length this matter of the need to ensure safety and the absence of errors with respect to CPGS, drawing in part on the knowledge of several members who have been involved for many years with strategic command and control. Some observations follow. 1. Ensuring safety and security is a system problem. Errors can occur in any of many parts of the overall system for handling and employing weapons: for example, during production, handover to the military customer, transport to a military base, warehousing, selection of ordnance to be loaded on an opera- tional platform, handling within the platform, the order to use a particular type of weapon for a particular target, the choice of a weapon consistent with the command order, and the delivery of the weapon to the correct target. And, when weapons are returned to storage, decommissioned, and destroyed, additional opportunities arise for problems. The events that led to the recent incident involv- ing the unintended transport of nuclear weapons on a B-52, followed by many hours during which the missiles sat unattended on the airplane at Minot Air Force Base, North Dakota, and Barksdale Air Force Base, Louisiana, included the errors made by support personnel in mistaking nuclear weapons for unarmed missiles to be destroyed (despite distinctive markings) and the failure of a series of support personnel and flight-crew members to fully check what weapons were being hung on a B-52 for transport and what weapons were on an arriving B-52. Ultimately, the responsibility lies with those who designed the system and those who failed to monitor the detailed performance of the redundant system and the many partial failures that must have preceded this major lapse. 2. Software problems at the “front end” are a special system issue. Those working to reduce safety and security risks to a minimum are typically associated with the weapon system program, such as the CTM program, but the possibility exists—at least in principle—for errors to occur between the time of decision, its interpretation, translation, encoding, and transmission, and the time at which the message to execute is received on the weapon system platform. Especially in a fast-track system such as the CTM is intended to be, the possibility always exists for software errors that are not detected early. A program to ensure safety, then, must include the full end-to-end process, including aspects of command and control over which the program office has no control. 

MILITARY ISSUES 57 3. Errors are often correlated rather than independent. As illustrated by the recent B-52 fiasco, error or complacency by one person or one group of people can be “passed on,” so that a sequence of intended checks turns out to be an initial failure to check followed by a sequence of pro forma nods. That is, what should have been sequential independent checks are instead correlated. In addition, of course, a system of checks and controls may fail if it has been poorly designed, so that the failure of a particular critical component means the failure of the whole. A familiar example is that of a building or area secured with formidable checkpoints with well-disciplined guards, but to which a construction crew is allowed easy entry by merely flashing a generic badge. In military systems, a parallel example might involve a critical command-and-control node. 4. Errors of procedure are more likely to occur when equipment needed for different purposes is co-mingled and when people have more than one mission. All else being equal, it is unwise for mechanics to have similarly shaped parts for dif- ferent devices on their immediate worktable; for soldiers to be carrying weapons and ammunition that would be prohibited for their current mission; or, more to the point, for conventional and nuclear weapons to be co-mingled in ways that would make it relatively easy for the wrong weapon to be used—whether accidentally, in anger, or as the result of conspiracy. 5. Security designs that include a combination of technical and procedural safeguards can be much more effective than either class separately. The recent B-52 event occurred because of a sequence of human failures. It might have been readily avoided if, for example, an electronic system refused to permit mounting of the missiles because of a test indicating that the missiles were nuclear-armed. An electronic system might have refused to permit nuclear-armed missiles from being removed from the warehouse without a special electronic key available only to logistics personnel recently certified for such activities. However, comput- ers and electronic systems are by no means foolproof and by no means do they always work properly. The classes of error that beset them, however, are different from those that can defeat processes dependent on consistent human adherence to procedures. Planning for the CTM The reason for including this discussion of safety is that the committee believes that those expressing worries about the safety and security of strategic weapons such those for CPGS are quite right to have concerns, but that solutions to the problem should come from careful system engineering rather than simple heuristics and impressions. That the B-52 incident represents an “unimaginable” lapse in the handling of nuclear weapons does not mean that all systems for han- dling, controlling, and using nuclear weapons (or strategic conventional weapons) are equally likely to have such mishaps. Different processes and protections are used for different weapon systems (e.g., B-2s, B-52s, ballistic missiles); some are 

58 U.S. Conventional Prompt Global Strike better than others, and the relative goodness (reliability and effectiveness) can be assessed by independent reviewers with in-depth knowledge. Recognizing the potential for error or loss of control of security or safety, the committee was very impressed by the preventive measures contained in the Navy’s plan for the CTM. The committee was briefed in detail on the proposed missile and shipboard modifications and the operational procedures that would provide CTM command-and-control and nuclear surety for SSBNs deployed with both nuclear and conventional Trident missiles. Among these measures are separate safes for the firing keys of the nuclear-armed and the conventionally armed missiles (one safe would be held by the commanding officer, the other by the executive officer), incompatible electrical interfaces, two physical blocking elements in the firing circuit in the missile, software interlocks, physical examina- tions on loading, and unique missile designators. Many standard SSBN nuclear surety measures apply. Standard nuclear surety procedures in system development will also mitigate the risk of an accidental nuclear launch in a CTM engagement. Personnel from the Naval Surface Warfare Center, Dahlgren Division, Virginia, who write the Trident fire-control software are closely monitored in a Personnel Reliability Program. Dahlgren personnel independently verify missile software developed by Lockheed Martin and vice versa. OSD periodically conducts an extensive 3-week review for all system changes. CTM-equipped Trident submarines would not be the first nuclear-capable mixed-load platforms. In the 1980s, attack submarines carried nuclear-armed land-attack Tomahawk cruise missiles in addition to conventionally armed anti- ship Tomahawks. Earlier in the Cold War, smaller nuclear weapons for antisub- marine warfare (antisubmarine rockets and submarine rockets) and antiair warfare (one of the family of Standard Missiles) were carried together with conventional weapons on surface ships and attack submarines. Furthermore, SSBNs routinely operate with mixed loads during fleet commander’s evaluation tests, during which nuclear payloads are switched out with test payloads before beginning a strategic patrol, and these reconfigured missiles are fired during the patrol under operational conditions. In the committee’s opinion, the Navy’s Strategic Systems Programs (SSP) presentations to the committee address the nuclear surety issue well. It is clear that SSP recognizes the additional risks related to CTM and is exercising due dili- gence in its plans to mitigate those risks. SSP’s track record gives one confidence. However, owing to the magnitude of the consequence of an accidental launch and the small amount of time that commanders in the field might sometimes have in prompt global strike engagements, the committee recommends the following: in addition to the risk mitigation measures proposed by SSP, OSD should appoint a red team to review thoroughly SSP’s plans, searching specifically for ways in which, perhaps due to a series of concurrent failures, an accidental launch of a 

MILITARY ISSUES 59 nuclear weapon might occur in an intended CTM engagement. SSP has used aggressive red teams in the past with excellent results. With the above proviso, the committee concludes that the risk of an accidental launch of a nuclear weapon in a CTM engagement can be made very low, and it believes that the risk of an accidental launch should not by itself be a reason to decide against developing the CTM. Findings and Recommendations The committee reached the following conclusions: • Importance. The CPGS mission is important and worthy of near-term priority and action. Indeed, extremely negative public reaction would be under- standable in a few years if the DOD were unable to accomplish crucial conven- tional strikes (e.g., against terrorist leaders or terrorists moving weapons of mass destruction, or against a rogue state that continued to fire missiles at an allied capi- tal for a period of hours) because of U.S. failure to have provided the option. • Near-term options. The only credible near-term (2 to 3 year) option is the Conventional Trident Modification and (with an additional year or 2 delay) a variant proposed by the committee for consideration, referred to as CTM-2. The Minuteman option, which might have been expected to be a contender for the near term, turned out not to be as attractive as might have been expected (see Appendix I). • Longer-term options. For the mid-term (e.g., around 2015), at least one additional option is available, the SLGSM launched from SSGNs. Thereafter, land-based options (CSM-1 and CSM-2) are proposed, with boost-glide capability if high-risk R&D proves successful over the next few years, as well as hypersonic cruise-missile options. These options are best seen as potential long-term options worthy of near-term R&D, but with IOCs not to be expected before about 2020. • The CTM. The near-term CTM would be effective for an important class of missions, it would be marginal for others, and ineffective for others. Describing the CTM as a niche weapon is appropriate. The committee emphasizes, however, that a niche weapon may be highly valuable if it provides operational capability for addressing critical situations, which would be the case with respect to CTM for several of the scenarios considered. The technical means for ensuring the nuclear safety of a CTM system ensure that the risk of an accidental launch of a nuclear weapon in a CTM engagement can be made very low. For the reasons explained in Chapter 3, the committee believes that it is highly unlikely that a launch of a conventionally armed Trident would be misinterpreted as a nuclear attack; that the chances that such a launch would trigger an immediate nuclear response is very low and could be reduced even further by means of established cooperative measures; and that the “ambiguity” issue is not a reason to forgo the capability that CTM would afford. 

60 U.S. Conventional Prompt Global Strike • An alternative. The CTM-2 could be an immediate follow-on to the CTM, or possibly an alternative, albeit one that would add to delay in IOC and would have to build heavily on the development and testing of the CTM, as would the SLGSM. The CTM-2 would have greater payload volume than the CTM and, being a two-stage missile, under some circumstances could be distinguishable from the three-stage CTM to observers of the CTM-2 launch and trajectory. • Enablers. A number of enabling activities are essential to mission success for CPGS. These activities, such as the precise determination of aimpoints, will sometimes have been done in advance and if so will not be a limiting factor, but they could also need to be done in a matter of an hour or so. Regardless of how quickly they must be accomplished, the quality of the enabling activities is critical, and the demands on those activities will grow over time if the ambition is to be able to strike moving targets. Major efforts are needed with respect to the enabling activities, not just the CPGS platform and weapon system. • Avoiding excessive constraints on R&D. A congressional prohibition on CPGS R&D building on the Trident missile would have serious adverse conse- quences for almost any CPGS option, causing delays of at least 4 or 5 years. If Congress should allow Trident-related R&D but not authorize the CTM’s deploy- ment, the CTM-2 or SLGSM availabilities would not be much affected—perhaps by a year or so. • Special issues. The committee recommends the following: (1) Congress should require that all CPGS options be developed with concepts of operations meeting very high, strategic, levels of safety and security—comparable to or better than the concept for the CTM, and planning for accomplishing this should include a review of command-and-control software, not just of weapon system issues, as well as rigorous red teaming to detect problems; (2) OSD should appoint a red team to thoroughly review the Navy’s plans, searching specifically for ways in which, perhaps due to a series of concurrent failures, an accidental launch of a nuclear weapon might occur in an intended CTM engagement; (3) options for increasing the number of warheads per CTM, giving the CTM increased capabil- ity against terrain-protected targets, and perhaps improving the lethality of the flechette-based weapon used on the CTM (and CTM-2), should be examined immediately, since such options are potentially important and may be feasible even in the initial deployment; and (4) Congress and the DOD should resolve the pure-load versus mixed-load issue on its merits, adjusting the various options accordingly so that they are measured by the same assumptions.