Tearing Down the Nuclear Firewall


In the U.S. nuclear community, you’ll often hear a strangely contradictory statement about nuclear weapons. It goes something like this: “We have nuclear weapons so that nuclear weapons will never be used.” U.S. nuclear deterrence, however, hinges on the assumption that adversaries believe that the United States has a functioning stockpile of nuclear weapons that can and will be used. In recent decades, arms control, nonproliferation agreements, and confidence-building measures have reduced the possibility of a strategic nuclear exchange between Russia and the United States. However, the risk of a conventional military crisis in Europe, the Middle East, or Asia escalating into a theater nuclear war remains.

The U.S. military needs to prepare its conventional forces to fight through a limited nuclear war. Right now, that planning and training is not apparent. The challenge is that U.S. political and military leaders do not encourage critical discussions on theater nuclear weapons use — every pertinent detail about the nuclear stockpile is classified, and every debate includes references to Cold War strategic weapons. In an ideal world, the United States wouldn’t use nuclear weapons if an adversary backs down in the face of a credible nuclear challenge. However, the existence of a nuclear taboo — that political leaders are restrained from first use of nuclear weapons — and Cold War fears of a strategic nuclear exchange between Moscow and Washington raise questions about the operational value of nuclear weapons. And yet, the issue of limited nuclear war isn’t going away.



Any time there is a confrontation with a nuclear-armed nation, U.S. policymakers and military leaders are thinking about the possibility of escalation. This can happen during a standoff in the South China Sea, while facing a crisis with Russia threatening the Baltic States, or when North Korea launches a ballistic missile over Japan. And while the senior decision-makers are asking “what if,” there has been a very distinct hesitation by defense analysts and military planners to think about what happens after a limited nuclear exchange. It’s been deliberately hard to get past the conventional-nuclear firewall. Does the conventional fight continue after the first nuclear detonation? Isn’t escalation to a strategic exchange a foregone conclusion, and if so, isn’t it moot to plan for continued conventional operations? That shouldn’t be an acceptable response, and some in the U.S. military are working to change that attitude.

Past Efforts to Plan for Limited Nuclear War

The U.S. government has a history of making plans for limited nuclear war. The plans hinged on having confidence that it could control escalation toward a strategic nuclear exchange. Thanks to accounts by Fred Kaplan, Lawrence Freedman, and Thérèse Delpech among others, we have a general sense of the Cold War history in which the U.S. nuclear posture changed from one of superiority in the 1950s to one of being slowly eclipsed by the Soviets in the 1960s. Arms control and nonproliferation talks started reducing the number of nuclear weapons, leading to a stable balance between the two main powers. In the 1970s and 1980s, U.S. administrations sought to pull back from “assured destruction” plans and discussed the possibility of limited nuclear strikes to achieve political objectives. For instance, the development of “flexible response” options would allow for using nuclear weapons in military conflicts, without going to a full strategic exchange.

During the Cold War, U.S. military forces had plans for using tactical nuclear weapons in Europe, in part because it was better than opting directly into a strategic nuclear exchange in the event of a Soviet attack. People remember President Ronald Reagan reaching out to the Soviet Union’s leadership in his desire to decrease nuclear weapons of the two superpowers, and stating that “a nuclear war cannot be won and must never be fought.” He said that in his 1984 State of the Union address, while at the same time, his administration was deploying Pershing 2 nuclear missiles and nuclear-armed, ground-launched cruise missiles in Europe, The deployments were in response to Soviet deployments of SS-20 intermediate-range nuclear missiles in Eastern Europe. In fairness, the NATO decision to deploy new U.S. nuclear weapons in Europe was made in 1979 during the Carter administration; Reagan was continuing previously established security plans and did not initiate this action.

When the Soviet Union collapsed in 1991, the United States stood alone as a unitary superpower. As a result, American military planners began to lose their expertise defending against adversaries with nuclear, biological, and chemical weapons. Some began to assume a magic firewall existed under which conventional wars would be fought by the geographic combatant commander, and if the conflict escalated past the firewall into nuclear warfare, U.S. Strategic Command would take over. In other words, strategic nuclear war was always someone else’s problem, not that of the geographic combatant commands, who were busy with counter-terrorism operations, tracking illicit smuggling rings, and building partnership capabilities. Even at the senior war colleges, when a wargame escalates to nuclear use, the game ends. No one plays through the aftermath of the first use of nuclear weapons, assuming that they can no longer achieve their objectives.

Developing an American Theory of Victory

In the face of growing Chinese and Russian power, the U.S. military is starting to discuss conventional-nuclear integration — the concept of integrating the use of nuclear weapons within theater plans to fight a conventional war against a nuclear-armed adversary. The 2018 Nuclear Posture Review notes that “every U.S. administration over the past six decades has called for flexible and limited nuclear response options,” and it warns that “limited nuclear escalation” by Russia or China to secure objectives within a theater of operations will not succeed. Brad Roberts has pointed out that Russia and China have “theories of victory” for using nuclear weapons below the threshold of strategic conflict, while the United States does not. While the military is just now socializing the idea of conventional-nuclear integration, it is not a new concept. Vincent Mazo and Aaron Miles see conventional-nuclear integration as “managing escalation in confrontations with nuclear-armed adversaries” as “an essential element of U.S. national security strategy” in 2016. Prior to that, Jeffrey Larsen and Kerry Kartchner released an edited volume On Limited Nuclear War in the 21st Century that offered several points of view on how the United States might prepare for this scenario.

While the academics have been busy, U.S. military leaders are not used to thinking about nuclear warfare. Conventional-nuclear integration is still very much a concept under development. Gen. John Hyten, former head of U.S. Strategic Command, has talked about how strategic deterrence should include both nuclear and non-nuclear weapons — that conventional, precision-strike munitions could offer that threat of force, previously made only by nuclear weapons, to deter an adversary (in some cases). Conventional-nuclear integration appears to go past that point of nuclear weapons only being used as a deterrent. If an adversary uses a nuclear weapon in theater (i.e., not against the continental United States), U.S. forces will have to continue conventional operations while considering how to compel the adversary to cease nuclear weapons use. This requires military planners to consider employment of tactical nuclear weapons while accounting for escalation risks. If U.S. planners are unprepared to respond to this scenario, it may in fact encourage continued nuclear attacks.

It’s all well and fine for the military to talk about conventional-nuclear integration, but are civilian policymakers ready for limited nuclear war? Civilians, after all, are the ones in the U.S. system that make the final decision about nuclear use. History has shown that the U.S. and former Soviet Union leadership have been decidedly pessimistic about using nuclear weapons, even as military leaders were planning for their possible use. Despite the U.S. military’s best-laid concepts, politicians may take significant steps to stop them from becoming official policy. A nation’s nuclear posture is not just the sum of its nuclear weapons and declared doctrine, but also how the politicians think and talk about nuclear weapons. As such, there are several challenges that have prevented the successful socialization of limited nuclear war theory.

Building Toward a Better Nuclear Policy

Thirty years after the Berlin Wall fell, many people still view nuclear weapons in terms of the Cold War — that the only possible outcome of any nuclear weapons use will be an apocalyptic, all-out nuclear exchange. Likewise, there is an assumption that there is no middle ground when facing a nuclear-armed adversary. Many believe that “the only winning move is not to play,” to quote War Games. Russian and Chinese officials don’t believe that, and they have embraced a role for nuclear weapons in local, regional, and strategic environments. But this Cold War fallacy affects views on U.S. defense strategy, modernization efforts, and political discussions. We can see this on both sides of the political aisle. If the politicians and civilian policymakers do not see a contemporary U.S. theory of victory for nuclear weapons use, then there will be no successful implementation of a conventional-nuclear integration concept.

Discussions outside the Pentagon on nuclear-use scenarios often disregard the possibility of tactical nuclear warfare. Both military and civilian leaders have stated that any nuclear weapon is by nature a strategic weapon. Well, of course it is, in terms of global political effect. That doesn’t mean that officials should hide behind the term “non-strategic nuclear weapons,” which is not an effective descriptor for military operations. Tactical nuclear weapons are designed to be used within a defined theater of operations and against military, not civilian, targets. It’s not that hard. Conventional-nuclear integration requires consideration of the tactical application of nuclear weapons, distinctly short of a strategic nuclear exchange.

The U.S. government needs to discuss nuclear weapons capabilities and reliability more openly to improve policy and analyses. Currently, the public has to accept without debate the arcane and ambiguous statements of the U.S. nuclear community, and take on faith that they have the right solution for future defense scenarios that involve the use of these complex weapons. That’s just not good enough. Keeping the recent joint publication on nuclear operations behind a “For Official Use Only” firewall does not help the U.S. military explain contemporary nuclear strategy and operations to the greater national security enterprise or to the general public. It also hampers America’s ability to include allies in the discussion of nuclear weapons employment in their countries. These are, again, Cold War rules kicking in, which makes it difficult to have open analysis and debates on the issue of limited nuclear war (or any aspect of nuclear deterrence operations, for that matter).

The national security enterprise and the general public need to understand the U.S. military’s concept of nuclear weapons use and its associated theory of victory. Indeed, the debate has already started, with the nuclear modernization program that was started under the Obama administration. To successfully engage in this debate, the U.S. government needs to acknowledge that contemporary nuclear weapons scenarios will not look like the Cold War. The national security enterprise should understand that tactical nuclear weapons are part of the military’s toolkit. In order to gain the trust of policymakers and politicians, the Defense Department needs to talk plainly about basic facts regarding nuclear weapons’ capabilities, locations, and use. Only then can the U.S. military confidently say that it has integrated conventional and nuclear operations.



Al Mauroni is the director of the U.S. Air Force Center for Strategic Deterrence Studies and author of the book, Countering Weapons of Mass Destruction: Assessing the U.S. Government’s Policy. The opinions, conclusions, and recommendations expressed or implied within are those of the author and do not necessarily reflect the views of the Air University, U.S. Air Force, or Department of Defense.

Image: U.S. Air Force (Photo by Sgt. Matthew Plew)