New Nuclear Cruise Missile Won’t Control Escalation, Will Erode Stability

Arms Control Today recently reported on emerging details of the Air Force’s plan for the long-range standoff weapon (LRSO). The LRSO is a replacement for the Air Force’s current, 1980s-vintage air-launched cruise missile (ALCM). The Air Force plans to build 1,000-1,100 of the new cruise missiles at a projected acquisition cost of about $9 billion.

After adding the $7-9.5 billion cost of life-extension for the associated warheads (according to estimates of the National Nuclear Security Administration), the total cost of replacing the existing ALCM could be close to $20 billion. 

Producing a replacement for the nuclear-tipped ALCM is a bad idea. The escalation control argument that is a key driver of the case for the LRSO is fundamentally flawed, and the U.S. would be better served by using some of the money for acquisition of a new conventional long-range standoff capability.

Why ALCMs?

The original military rationale for developing the ALCM emphasized the cruise missile’s value as a standoff weapon that could ensure penetration of Soviet air defenses. The B-52’s ability to penetrate Soviet airspace was under pressure in the late 1970s and early 1980s, and standoff capability allowed a B-52 to hold strategic targets at risk in relative safety despite its large radar cross section.

Nuclear-armed cruise missiles also supported the “countervailing strategy” introduced by President Jimmy Carter. Their high accuracy and relatively lower yield (a 1-150 kiloton variable-yield W80-1 warhead is mounted on the ALCM) were believed to be well-suited to counterforce strikes against Soviet military formations.

Furthermore, as Greg Thielmann writes in a recent Threat Assessment Brief, cruise missiles (including submarine- and ground-launched cruise missiles, as well as ALCMs) “…narrowed enemy pre-emption possibilities while providing U.S. nuclear targeteers with a wider range of strike options.” Air defense against cruise missiles and gravity bombs is much more challenging than simply defending against planes seeking to drop gravity bombs.  

Cruise Missiles in Today’s Environment

One of the arguments the Department of Defense puts forth in favor of the LRSO, is that the new system will allow the United States better control over escalation through its possession of a lower yield option that can deter or respond to a lower yield attack without forcing the United States to resort to the use of a more destructive (and therefore potentially less credible) high-yield intercontinental ballistic missile (ICBM) or submarine launched ballistic missile (SLBM). In the Project Atom report from the Center for Strategic and International Studies, Dr. Thomas Karako claims that the United States should “…maximize flexibility and credibility for the future…” in order to deter and/or defeat limited nuclear use.

Dr. Karako posits that the United States requires a low step on the escalation ladder (in addition to the B61-12) that could deter or respond to limited nuclear use of the sort envisioned by Russia’s alleged “escalate to de-escalate” doctrine.

Chinese advances in anti-access/area denial technology (A2/AD) likely also make the LRSO appealing to Pentagon planners who are concerned about the U.S. ability to strike targets related to Chinese A2/AD systems.

Will Escalation Control Work as Theorized?

The belief that a nuclear weapon can provide the United States with control over escalation of a conflict suggests that a nuclear war can be contained. Advocates of the concept describe low-yield nuclear weapons as comparatively low rungs on the escalatory ladder. However, this theory implies that nuclear weapons exist in the same continuum as conventional weapons. Thus a low-yield device is just the next rung up the ladder from a conventional weapon.

That leaders could be confident of limiting the use of nuclear weapons in an environment that is chaotic and fraught with tension or even during a hot war, is unrealistic. Decision-makers on two sides of a conflict cannot expect their counterparts to carefully calibrate their responses on the basis of weapons yields in a limited nuclear attack. Why wouldn’t a foreign leader assume, once the United States has crossed the nuclear threshold, more incoming warheads are imminent and therefore the leader should respond with every warhead available before losing them? Regardless of whether an attacker uses a 15-kiloton warhead (about the yield of the Hiroshima blast) or a 150-kiloton yield (the upper range of the W80-1/4 warhead), escalation would likely be prompt and brutal, rather than measured and precise.

In a June 25 House Armed Services Strategic Forces Subcommittee hearing, Deputy Defense Secretary Robert Work testified that “Anyone who thinks that they can control escalation through the use of nuclear weapons is literally playing with fire. Escalation is escalation, and nuclear use would be the ultimate escalation.” This is sound advice and seems to contradict one of the Pentagon’s primary justifications for obtaining the LRSO.

Conventional is Better  

The Air Force claims that it does not plan to produce a conventional LRSO variant. However, it would seem more prudent for the Air Force to scrap the nuclear-tipped LRSO and buy more conventional air-launched cruise missiles. Further investment in conventional standoff weapons would provide the Air Force with a long-range capability that would be more readily useable without the strategic uncertainty questions associated with a nuclear/conventional dual-variant system that exists with the ALCM today.

If the current ALCM were employed against an adversary, the adversary might be obligated to respond as though the weapon carried a nuclear warhead. It would be irresponsible for the United States to rely on an adversary assuming the best case. And, it would be destabilizing to build into future forces ambiguity on whether cruise missiles carried nuclear or conventional warheads. Former British Minister of Defense Philip Hammond drew attention to this problem when he argued against British development of a submarine-launched nuclear cruise missile, writing “A cruise-based deterrent would carry significant risk of miscalculation and unintended escalation. At the point of firing, other states could have no way of knowing whether we had launched a conventional cruise missile or one with a nuclear warhead. Such uncertainty could risk triggering a nuclear war at a time of tension.”

Developing the LRSO would also be inconsistent with the nonproliferation and disarmament ideals espoused in Prague by President Barack Obama during his first term, and reaffirmed in Berlin in 2013. Building a replacement system for the ALCM is not reducing the role of nuclear weapons in U.S. national security strategy, but rather extending the expiration date of an unnecessary nuclear weapon into the indefinite future. Such an investment in nuclear warfighting would be fitting for Dr. Strangelove’s Gen. Buck Turgidson, but hardly a fitting legacy for a winner of the Nobel Peace Prize.

Lawmakers should press the Air Force and STRATCOM on why the United States, after investing billions of dollars on future submarine-launched ballistic missiles, intercontinental ballistic missiles, and long-range penetrating bombers armed with the B61-12 nuclear gravity bombs, should spend billions more on the  redundant capabilities of a nuclear LRSO.