Five Myths About a Controversial Nuclear Weapon

June 20, 2017

For special access to experts and other members of the national security community, check out the new War on the Rocks membership.

Last week on Capitol Hill, Secretary of Defense Jim Mattis revealed the rigor of the ongoing Nuclear Posture Review:

We’re looking at each leg of the triad and we’re looking at each weapon inside each leg. What I’m looking for is a deterrent that will be most compelling to make certain that these weapons are never used.

Feinstein, however, pressed Mattis on one nuclear weapon in particular that is at the heart of a major debate about deterrence and the defense budget: the air-launched nuclear cruise missile. The senator from California challenged the idea that it serves as an effective deterrent and said that she didn’t see why it had to be modernized along with the ballistic missile submarine, the long-range bomber, and the land-based intercontinental missile.

While there is bi-partisan consensus on the need to modernize U.S. strategic nuclear delivery systems, some analysts and prominent political figures like Feinstein have questioned the need to replace the aging air-launched cruise missile, the AGM-86B or ALCM, with the Long Range Stand-Off Weapon (LRSO).

In War on the Rocks and other publications, opponents of the LRSO have expressed significant concerns about the system. First, they see the LRSO as a redundant capability that is not necessary to meet military requirements. Second, they argue that nuclear-armed cruise missiles are inherently destabilizing, could undermine strategic stability, and increase the risk of nuclear war. Third, they insist that if the United States were to cancel the LRSO, it could convince other countries who currently deploy nuclear-armed cruise missiles to eliminate their systems. Fourth, they contend that U.S. allies would likely support the elimination of nuclear-armed cruise missiles. And finally, they view the existing strategic modernization program as unaffordable, and therefore, argue that the LRSO should be cancelled.

These arguments are made by respected experts, many of whom I’ve worked with closely throughout my career working on these very issues, most recently as assistant secretary of state for arms control, verification, and compliance. That said, after reviewing their arguments, I’ve found them to be unconvincing. While I’ll briefly address the military requirements for the LRSO, those issues have been addressed in more detail by other authors who have appeared in this publication. In tackling their arguments one by one, I take a slightly different approach, focusing on the impact of the LRSO on strategic stability, arms control, and U.S. extended deterrence commitments to its allies as well as the issue of cost.

Myth #1: The LRSO is Not Necessary to Meet U.S. Military Requirements

Opponents of the LRSO insist that it is not needed to meet U.S. military requirements. They argue that the new B-21 penetrating bomber armed with the B-61 gravity bomb will be able to hold most adversary targets at risk. However, opponents generally fail to acknowledge that both Russia and China are rapidly improving their air defense capabilities and accompanying anti-access/area denial (A2/AD) strategies. For example, Russia is developing advanced air and missile defense systems such as the S-400 and S-500 that will allow it to engage enemy aircraft at a range of up to 125 miles. As a result, the United States likely needs a stand-off capability to hold certain heavily defended targets at risk. The LRSO provides this and will help ensure that America’s remaining B-2 and B-52 bombers remain effective nuclear delivery platforms through the 2040s.

Opponents also claim the United States can meet its military requirements with existing conventional cruise missiles, especially the extended-range variant of the Joint Air-to-Surface Standoff Missile or JASSM-ER.   Last year, Franklin C. Miller — a veteran defense official who worked for three presidents — rebutted this notion in written testimony to the Senate:

Since the role of ALCM-B and the LRSO is to deter nuclear attack by posing a credible nuclear retaliatory capability, there should be no confusion as to whether a conventional cruise missile can substitute in that role: it cannot.

That’s not to say that the United States shouldn’t continue to deploy systems like JASSM-ER to meet its conventional military requirements. However, with an estimated range of around 1000 kilometers, the JASSM-ER may not have the range necessary to hold all key Chinese and Russian conventional military targets at risk. We also do not know if the JASSM-ER will be effective against highly sophisticated Chinese and Russia air defenses in the future. This is why I’ve argued elsewhere that the United States should develop a conventional variant of the LRSO, similar to the conventional variant of the existing ALCM, the AGM-86 C/D or CALCM.

Myth #2: Nuclear-Armed Cruise Missiles are Inherently “Destabilizing”

In broadsides against the LRSO, we hear that nuclear-armed cruise missiles are inherently destabilizing. However, throughout the history of the nuclear age, bombers and air-launched cruise missiles have generally been seen as stabilizing. Former undersecretary of state for arms control and international security Rose Gottemoeller stated in July 2016:

Arms control has generally given a “discount” to bomber weapons because they are seen as the least threatening to stability, because they pose the smallest risk of surprise attack.

Franklin Miller supported this assessment in the same written testimony cited earlier:

[T]he strategic stability provided by bombers and cruise missiles was recognized in the special counting rules applied to them during the Cold War in the START Treaty and much more recently in this decade by the New START Treaty.

Contrary to what opponents argue, the LRSO is not a “first strike” or “decapitation” weapon. If they were to be used, the LRSO would be delivered by long-range bombers. The process of alerting these bombers would be observable by national technical means and the aircraft would most likely take hours to deliver weapons to targets once the order was given. Indeed, former deputy secretary of defense John Hamre has described the LRSO as “the least likely way to conduct a decapitation strike.”

According to Will Saetren of the Ploughshares Fund “an enemy would have no way of knowing if they were under conventional or nuclear attack” because cruise missiles “come in conventional and nuclear variants.” He darkly warns, “This could easily lead to miscalculations and could trigger a nuclear war.” However, the notion that the dual-capable nature of cruise missiles is inherently destabilizing finds little support when examined against the historical record. For example, the United States has deployed conventional and nuclear-armed cruise missiles (e.g., ALCM, CALCM, TLAM/N) for over 30 years without undermining strategic stability or triggering an accidental nuclear war. Russia also continues to deploy similar systems, including their next generation nuclear-armed, air-launched cruise missile, the KH-102, and has employed its conventional variant, the KH-101, in Syria.

Myth #3: Canceling the LRSO will Convince Other Countries to Eliminate Their Nuclear-Armed Cruise Missiles

William Perry, Andy Weber , and Will Saetren have all argued that cancelling the LRSO could lay the foundation for a global ban on nuclear armed cruise missiles, and if the United States leads by example by eliminating its nuclear-armed cruise missiles, other states that possess them could follow suit. A review of the historical record shows that this is unlikely. For example, when the United States retired the TLAM/N sea-based, nuclear-armed cruise missile in 2010, other states did not follow Washington’s lead. What possible incentive would Russia have to give up its system if the United States cancelled the LRSO unilaterally, especially since it just completed the modernizationj of its own nuclear-armed cruise missiles? Nor is it likely that cancellation of the LRSO would have any impact whatsoever on Indian or Pakistani nuclear modernization.

And even if other countries were prepared to negotiate a global treaty banning nuclear-armed cruise missiles, there are serious questions about how such a ban would be verified, especially if nations retained the right to deploy conventionally-armed cruise missiles. Verification of such a ban would be highly challenging, and the proponents of a ban have not provided a convincing argument of how such a treaty could be effectively verified.

Myth #4: U.S. Allies Will Support a Nuclear Cruise Missile Ban

Opponents also argue that U.S. allies would likely support negotiation of a global ban on nuclear-armed cruise missiles, and that such a ban would help allies manage their domestic political challenges associated with nuclear disarmament. As the assistant secretary of state responsible for arms control and nuclear policy issues, I engaged allies frequently on the U.S. nuclear modernization program. And while some allies (such as Japan and the Netherlands) certainly face domestic political pressure to support nuclear disarmament proposals such as the Nuclear Weapons Ban Treaty, it is hard to see how the cancellation of the LRSO by the United States would alleviate those pressures.  Furthermore, no ally covered by U.S. extended deterrence commitments has expressed support for negotiating a treaty banning nuclear-armed cruise missiles.

To the contrary, allies are increasingly concerned about the development by Russia and China of sophisticated A2/AD systems, including advanced air defenses, designed to deny the United States the ability to project power forward during a conflict or crisis. Therefore, the development of advanced, stand-off range systems like the LRSO will be critical in assuring allies that the United States can maintain effective deterrence. And unlike submarines and land-based intercontinental missiles, bombers armed with air-launched cruise missiles are a visible way to demonstrate commitment to allies, and signal resolve to adversaries during a crisis. At a time when allies are growing increasingly concerned about the United States’ commitment to their security, it’s hardly the time to stoke additional concerns about that commitment by unilaterally cancelling the LRSO.

Myth #5: The United States Can Save a Lot of Money by Canceling the LRSO

There are serious questions over whether or not the overall U.S. strategic nuclear modernization program is affordable within existing and projected defense budgets. The Congressional Budget Office estimates that the costs of the nuclear modernization program could amount to over $1.2 trillion. As a result, opponents have called for cancelling the LRSO as an affordability measure. In my view, concerns about the costs and affordability of the overall modernization program are warranted, but it’s questionable whether cancelling the LRSO would generate significant savings. Between fiscal years 2016 and 2020, the Department of Defense is slated to spend approximately $94 billion on nuclear modernization overall. During that same time period, the Pentagon expects to spend $1.78 billion on the LRSO out of a total cost of $8.3 billion. This represents only about 2 percent of the strategic modernization budget. Even when procurement of the system begins in the mid-2020s, it’s unlikely that that percentage will grow significantly.

The LRSO: A Critical Capability

With Chinese and Russian military power growing — especially in terms of its A2/AD capabilities — the LRSO will play an important role in holding key adversary targets at risk. It is not a destabilizing weapon. Indeed, the historical record clearly shows that the LRSO is one of the more stabilizing weapons in a nuclear arsenal. Furthermore, claims that cancellation of the LRSO by the United States will lead other countries to eliminate their nuclear-armed cruise missiles are flawed and unsupported by the history.

Of all the arguments offered by opponents of the LRSO, the most credible appears to be that the current strategic modernization program as a whole is unaffordable. They very well may be right. However, cancelling the LRSO is unlikely to reap the cost savings that they seek. Therefore, other tradeoffs will likely need to be made in order to make the program affordable over the long-term. This will certainly be one of the key issues addressed in the on-going Nuclear Posture Review. However, based on its military capabilities, flexibility, and cost-effectiveness, it is critical that the LRSO remains a key part the strategic modernization program.


Frank A. Rose is a nonresident senior fellow for the Atlantic Council’s Brent Scowcroft Center on International Security. Rose served as assistant secretary of state for arms control, verification and compliance from 2014-17. From 2009 to 2014, Rose served as the deputy assistant secretary of state for space and defense policy.

Image: Air Force

We have retired our comments section, but if you want to talk to other members of the natsec community about War on the Rocks articles, the War Hall is the place for you. Check out our membership at!