Nuclear Assumptions and Cruise Missiles

Earlier this week, Secretary Clinton made a statement about the Pentagon’s plan to upgrade the nuclear arsenal. “The last thing we need, are sophisticated cruise missiles that are nuclear armed.”[1] The National Interest was quick to pile on, and declare that nuclear cruise missiles are “relics of the past.”[2] But are they? Hillary Clinton spent a good deal of time as Secretary of State, therefore her opinion on the matter is not something that can be dismissed as simply ‘election talk.’ However, that doesn’t mean she’s right. The National Interest claims, “the new air-launched cruise missile… is a redundant and destabilizing weapons system that offers no clear strategic value.” Cruise Missiles, especially the nuclear variety, are a topic of much strategic debate, and have been since their inception. To move down the acquisitions path of a new cruise missile and/or a new bomber ignoring nuclear policy is both naive and dangerous, therefore this conversation is critical. So why not dive into the issues and identify the underlying assumptions.

Strategic bombing doctrine holds that one must penetrate the defenses of an adversary to get to the target. For the first 70 or so years of aviation, that meant the bomber penetrated defenses to drop bombs on targets. In 1972, the bomber was the B-52, the targets were in Russia, and the bombs were nuclear. The Soviets began to develop a new missile system around that time, called the S-300. This air defense was unlike anything strategic bombing had seen before. The B-52 could not penetrate these defenses.

There are two ways to defeat any defense: (1) defeat it directly with a weapon it cannot defend against, or (2) overwhelm it with more than it can handle.  At the time, the only way to do either was with a ballistic missile, a penetrating bomber, or something new. The USAF could have attempted to overwhelm the defense with aircraft, but the losses would have been devastating. The S-300 was that good. The cost of a new penetrating bomber (the B-1) was described as “ridiculous.”^[3] So Congress opted for ‘something new.’^[4]

The National Interest is dead on target with its assessment that the ALCM was a stop-gap measure. Betts goes into much greater detail in describing the political climate of the time and the rationale behind those decisions. The USAF and Congress were faced with a quantity / quality decision.  The cruise missile held greater appeal to policy makers because it could combine quantity and quality, with an emphasis on quantity. The technology was simpler than a manned bomber; it allowed large purchases and rapid modernization.  It could be better faster, stay better longer, and could be fielded in large numbers. President Carter specifically noted in his decision that cruise missiles would extend the effectiveness of the B-52 fleet for at least another decade, allowing him to cancel the B-1, one of his campaign platforms. The Pentagon estimated that the B‑52/ALCM combination provided better performance over the B‑1 at 20% of the cost.[5] Early S‑300 systems could marginally detect cruise missiles.  Cruise missiles were small, with matching small radar cross-sections, resulting in less time for the cruise missile to be engaged.  When they were detectable, the cruise missile was too fleeting to engage effectively.  The cruise missile was practically immune to this new air defense.  The cruise missile could directly overcome the S-300.  This is the main reason the United States never pursued supersonic or hypersonic cruise missiles; the US never needed them.  The subsonic cruise missile was good enough.^[6] By the time radars and SAMs got better and faster, making them capable of detecting and destroying cruise missiles, the US had a significant number of cruise missiles and again did not need to pursue better/faster cruise missiles.  It was easier to overwhelm the defense with more cruise missiles than the S‑300 could handle. The ALCM was everything the US needed and wanted. In the 1980s and 90s, the strategic value was overwhelming.

But then the S-300 got better in a hurry.  Modern S‑300 systems can now track and destroy up to 36 targets simultaneously, including Cruise Missiles.[7]  Their success is no longer guaranteed. Therefore it is pertinent to revisit the underlying assumptions, and decide again if they are necessary, and determine if the strategic value remains.

So, what would make the nuclear cruise missile obsolete?

• Abandoning the air-breathing portion of the nuclear triad. ICBMs and SLBMs provide enough deterrence value. No aircraft delivered nukes means no need for a nuclear cruise missile.
• Abandoning the mixed bomber fleet. The B-21 is so good that a complete reliance on penetrating aircraft is acceptable. No “stand-off” bombers means no need for a nuclear cruise missile.

Therefore, when a politician running for president, or a policy maker making nuclear armed statements says there is no need for a nuclear cruise missile, they must also be willing to abandon one or both of the underlying assumptions for having the capability in the first place. Conversely, when the President and the Secretary of Defense double down on nuclear modernization, referring to the air-breathing force as the “bedrock of our security,”[8] they are saying that they are committed to one or both of those assumptions.

Abandoning the air component of the triad is not a new idea.[9] Three times the United States contemplated reducing the ‘nuclear triad’ to a dual force by eliminating the bomber portion.  The underlying assumption is that ballistic missiles provide enough deterrence value. All of our needs and wants with regard to first strike, second strike, survivability, etc. are fully encapsulated with ballistic missiles. There is strong case to be made that ballistic missiles accomplish exactly that. However, there is an equally strong case to be made that they do not. All three times, the US came to a conscious decision that the air-breathing leg of the triad remained necessary.^[10] In other words, ballistic missiles were not enough. Cruise Missiles trump Ballistic Missiles in accuracy by a factor of ten; they are cheaper by a factor of two, easier to operate and maintain, afford greater mobility and survivability, and are less susceptible to counterforce strikes.^[11]  To be sure, a penetrating bomber can accomplish this as well, however it is many times more expensive, with a much longer development time, an exponentially larger logistical tail, and risk to both bomber and crew.

Therefore, for the purposes of exploring the policy implications of a nuclear cruise missile, we must assume the US will continue to be committed to the air-breathing nuclear force. Today that force consists of the B-2 penetrating bomber dropping nuclear bombs and the B-52 standoff bomber launching nuclear-armed cruise missiles.[12] The quantity of aircraft and missiles suggests the B-52/ALCM plays a much larger role than B-2s dropping nuclear bombs.[13] This makes sense considering there just aren’t that many B‑2s. The National Interest claims that if the B-21 is fielded in large enough numbers, the B-52 will be retired and the cruise missile will no longer be needed. That means they believe the USAF will choose to go to an all-penetrating bomber force. In the 1980s the USAF had convinced Congress that a mixed fleet of penetrating bombers and cruise missile armed standoff bombers provided the best hedge against unknown advancements in SAM[14] technology.[15] This is the underlying assumption of the mixed-fleet. Is the assumption 40 years old? Yes, but that doesn’t make it wrong. There is no evidence to suggest this assumption is no longer valid. The cruise missile does continue to provide a hedge against SAM advancements. This is because we can modernize, improve, and upgrade cruise missiles faster, easier, and cheaper than we can aircraft. This allows the cruise missile to stay ahead of SAMs longer than aircraft can. But there is a top end to that hedge and the modern S-300 against the ALCM is that top end. The ALCM is at the end of its serviceable and upgradable lifetime. Therefore, if the mixed fleet is to remain, we need a new nuclear cruise missile.

The National Interest continued to describe the miscalculation risk of cruise missile usage. While it is true that the British abandoned a cruise-based deterrent because of the miscalculation risk, what they missed is that the British abandoned a sea-based cruise deterrent.

“Because cruise missiles can be launched without warning and come in conventional and nuclear variants, an enemy under attack has no way of knowing if he is facing a conventional our nuclear strike. That could cause a miscalculation that could launch a nuclear war.” Will Saetern, The National Interest

This is true only when the adversary detects the launch. In a sea-based cruise missile, it is rocket boosted prior to transitioning to a cruise system. The risk of miscalculation is there because you can’t hide the launch. A nation cannot hide the launch of a rocket from satellites, but it can hide an air-launched cruise missile. The adversary does not detect the launch, therefore does not miscalculate. The cruise missile is difficult to detect, and by the time detection does occur, the target is struck. Miscalculation is removed with an air-launched cruise missile of significant range.

That range is why the JASSM is not the US’ next nuclear cruise missile. The AGM-158 Joint Air-to-Surface Standoff Missile (JASSM) is actually very effective against modern air defenses.[16] The JASSM vs. the modern S-300 is analogous to the ALCM vs. the early S-300. However, the JASSM never had the range of a true standoff cruise missile. The original Tomahawk (nuclear capable) had a range of 1350 nm and the ALCM has a range of 1500 nm.  The JASSM tops out at 230 nm. The newer JASSM‑ER (extended range) can fly 650 nm, which puts it into the same class as the newest TLAM-D, range 700 nm, and the CALCM, range 680 nm.^[17]  That range must exceed early-warning to ensure the launch is not detected.

The last four presidents (including one named Clinton) were forced to make nuclear decisions in the “post-Cold War world” and each re-affirmed their commitment to the air-breathing nuclear force. Those presidents came from diverse backgrounds and made spectacular statements about our nuclear force in their campaigns. But when presented with the facts, were bound by reality. Today’s reality is one that includes a nuclear armed cruise missile. To waive off the development and acquisition of a new nuclear-armed cruise missile as having “no strategic value” is a statement that deserves analysis. Once cannot make that claim without investigating the underlying assumptions of the capability. If you want to get rid of the capability, you have to change your assumptions. Secretary Clinton does not want a nuclear-armed cruise missile. If elected, is she prepared to eliminate the air leg of the triad? Is she prepared to forge ahead without a hedge against unknown advances in SAM technology? If she is prepared to do that, then we do not need the nuclear-armed cruise missile. There is a strong case to be made for further reductions in our nuclear arsenal, including dramatic shifts in our dependence on nuclear weapons for strategic deterrence, but those cases must be viewed in a holistic manner. Previous White Houses and Pentagons have done just that, and they all came to the same conclusion because the underlying assumption for the capability remains valid.

“The ICBM… gives us incredible responsiveness… The air leg gives us tremendous flexibility… The sea-based gives you tremendous survivability. Those are options that I think the president has found, every president since President Eisenhower, has found those to be compelling reasons to keep the triad.” General Robin Rand, Commander, Air Force Global Strike Command

Angle of Attack, a journal of Air Power Strategy, will be visiting this topic many times in the future.

 

 

NOTES

[1] David Sanger and William J. Broad. “In Hacked Audio, Hilary Clinton Re-Thinks Obama’s Nuclear Upgrade Plan.” New York Times, Sept 29, 2016. http://www.nytimes.com/2016/09/30/us/politics/hillary-clinton-obama-nuclear-policy.html?_r=0

[2] Will Saetren. “Nuclear Tipped Cruise Missiles are a Relic of the Past.” The National Interest. Sept 30, 2016. http://nationalinterest.org/blog/the-buzz/nuclear-tipped-cruise-missiles-are-relic-the-past-17889

[3] Richard K. Betts, ed., Cruise Missiles: Technology, Strategy and Politics (Washington DC: The Brookings Institute, 1981), 69.

[4] Betts, Cruise Missiles, 83.

[5] “Carters Big Decision: Down Goes the B‑1, Here Comes the Cruise.”  Time Magazine, July 11, 1977.

[6] The opposite was true of the Soviet’s decision to field a supersonic cruise missile; theirs was not good enough to engage American Carrier Battle Groups.  The Raduga P-270 Moskit (NATO: SS-N-22 Sunburn) had a top speed of Mach 3 and was fielded in the early 1970s.  Previous Soviet sub-sonic cruise missiles were inadequate to penetrate USN Carrier defenses.  This missile showed promise in evading F-14 screens and Standard Missile/CIWS engagements.  It was too fast for all those defenses.  The Soviets later scrapped supersonic cruise missiles when they made a quality-vs-quantity decision.  They decided to go with a much larger number of cheap subsonic CMs over the more- expensive and harder-to-employ-and-maintain supersonic cruise missiles. Reference Betts, Cruise Missiles, 360.

[7] “S-300 Family,” Jane’s.

[8] Aaron Mehta, “Carter: Nuclear Triad ‘Bedrock of Our Security.” Defense News. Sept 26, 2016. http://www.defensenews.com/articles/carter-nuclear-triad-bedrock-of-our-security

[9] Don’t confuse this with President HW Bush’s decision to take the Bombers of alert in 1992. While that decision allowed a reshuffle of the strategic environment, it did not remove Bombers from the overall plan.

[10] 2001 and 2010 Nuclear Posture Reviews both contemplated the removal of the entire air-breathing nuclear force.  Both administrations and the Department of Defense concluded that the air-breathing leg was still required.

[11] David W. Kearn, “Facing the Missile Challenge: US Strategy and the Future of the INF Treaty,” RAND Corporation, 2012, 29-30.

[12] The B-1 is no longer considered a nuclear bomber due to past treaty limitations, not through any deficiencies in capability The 1991 START agreement placed limits on the number of heavy bombers and armaments on heavy bombers.  The US chose to implement those reductions on the B-1 force.  Reference “Treaty Between the United States of America and the Union of Soviet Socialist Republics on the Reduction and Limitation of the Strategic Offensive Arms.”  US State Department.  http://www.state.gov/www/global/arms/starthtm/start/start1.html

[13] Regardless of the warhead inside, the cruise missile is vulnerable to modern air defenses.  The United States saw this problem as early as the mid-80s and created a new subsonic cruise missile to deliver nuclear warheads, the Advanced Cruise Missile (ACM).  It attempted to incorporate stealth technology, allowing it to penetrate where the ALCM would not, removing the ALCMs vulnerability, and reinstituting the capability gap to the offense.  It would have been the answer to all the United States’ problems except that the ACM was a disaster.  It had accuracy issues, maintainability issues, reliability issues, carrier limitations and was a general disappointment. To be blunt, while the USAF had every confidence it would not be shot down; it had equal confidence it would not hit its target.

[14] Surface to Air Missiles. The S-300 really scared the USAF and they wanted a measure of risk mitigation against a similar technology jump.

[15] Betts, Cruise Missiles, 360.

[16] “Air Launched Cruise Missiles – AGM-158,” Jane’s IHS 360, https://janes.ihs.com/airoffense/cruisemissiles/display/1494641

[17] Tomahawk Land Attack Missile (TLAM) is the modern version of the US Navy’s long-range cruise missile.  The Conventional Air Launched Cruise Missile (CALCM) is the same missile as the USAF’s ALCM with a non-nuclear warhead.