In 1991, U.S. President George H. W. Bush decided to retire almost all the tactical nuclear weapons operated by the U.S. Army and the U.S. Navy. His reasons were simple: these short-range weapons were militarily useless and imposed significant burdens on the armed forces in terms of money, manpower, and time. Twenty-three years later, only one type of tactical nuclear weapon remains in the U.S. inventory: the B-61 gravity bomb. In addition to the several hundred B-61s located at home, the United States currently deploys around 180 of them in Europe, at bases in Belgium, Germany, Italy, the Netherlands, and Turkey. In the event of a nuclear conflict on the continent, NATO would deliver the bombs via U.S.-built F-15 or F-16 aircraft or European-built Tornado fighters, operated by some combination of Belgian, Dutch, German, Italian, and U.S. crews. Originally intended to prevent Soviet forces from penetrating Western Europe, the planes could travel as far east as Russia. But owing to their slower speed and lower altitude, they would be much more vulnerable to Russia’s ground-based air defenses than would longer-range strategic bombers and missiles.

Such impractical plans are remnants of the Cold War, when the conventional forces of the United States and its allies were thought to be so inferior to those of the Soviet Union that NATO tried to deter Moscow by threatening to use nuclear weapons first. Tens of millions of Germans, Poles, and other Europeans would have been killed in such a tactical conflict. But even at the time, few believed that the weapons would have been able to stop a Soviet attack. Since detonating tactical nuclear bombs would have likely triggered a strategic nuclear exchange, Western policymakers reasoned that the fear of such escalation would prevent the Soviets from attacking in the first place. But Soviet plans called for the massive use of nuclear weapons at the very onset of any form of conflict in Europe, making the tactical weapons themselves irrelevant.

Note: Some Russian sites lie outside the map area. Sources: Global Zero and the Natural Resources Defense Council

If tactical nuclear weapons had little military value during the Cold War, they have even less today. The weapons no longer serve their primary role of substituting for the weakness of the United States’ nonnuclear forces; as U.S. President Barack Obama himself has noted in response to the crisis in Ukraine, NATO now enjoys overwhelming conventional military superiority over Russia. Still, long-held assumptions are difficult to dislodge, especially when policy changes require the agreement of 28 member states. Moreover, some newer members of the alliance in eastern Europe, or at least their defense officials, take comfort in the symbolism of the continuing presence of U.S. nuclear bombs on the continent -- all the more so after Moscow’s recent incursion into Ukraine.

Maintaining such symbols will soon become very costly, however, because the aircraft designated to deliver tactical nuclear bombs are nearing the end of their service lives. Some will be replaced with a new version of the F-35 Joint Strike Fighter, a U.S.-built plane scheduled to be rolled out in the coming years. But giving the F-35 the capability to deliver nuclear weapons would add hundreds of millions of dollars to its already high price tag. The U.S. Department of Defense would also have to extend the service life of the B-61 bomb itself, to the tune of around $8–$10 billion. And hundreds of millions more dollars (or euros) would be required to upgrade nuclear storage facilities on the continent.

As U.S. and European defense budgets continue to shrink, it makes little sense to spend such large sums on an outdated strategy. Particularly in light of recent events in Ukraine, Washington and its European allies should invest that money in other military capabilities that would actually help defend the interests of NATO members. U.S. allies would be far better off if Washington allocated its scarce resources to maintaining effective conventional and strategic nuclear forces rather than a decaying vestige of a bygone era.

NUCLEAR WASTE

During the Cold War, the conventional military forces of the Soviet Union and other members of the Warsaw Pact seemed vastly greater than those of the United States and its allies. According to contemporaneous estimates, the Warsaw Pact enjoyed a ten-to-one advantage over NATO in standing army divisions, making it capable of quickly overwhelming NATO forces with a surprise attack on Western Europe. It is now clear that these assessments overestimated the strength of the communist forces, but at the time, they encouraged U.S. strategists to develop plans for limited nuclear wars. In their view, short-range nuclear weapons could compensate for NATO’s weak conventional forces while also implicitly threatening escalation to an all-out nuclear exchange.

Today, however, NATO has no need to compensate for its conventional weakness, since it enjoys conventional superiority over any possible foe. Whereas Russia currently has about one million men under arms, the United States will still have over 1.2 million active-duty military personnel even after its ongoing military drawdown is complete. Washington has at least as many armored vehicles, twice as many air force fighters, three times as many surface combatant ships, and ten times as many large aircraft carriers as Moscow. NATO’s European members, meanwhile, have two million soldiers, many of whom would have fought for the Warsaw Pact before the Soviet Union’s fall. Most important, the United States and its allies enjoy a huge qualitative advantage over Russia, owing to the superior training and experience of the individuals who serve in NATO’s armed forces. And the United States’ intelligence, surveillance, and reconnaissance capabilities, supported by advanced space and airborne systems, to say nothing of its fighter aircraft and their precise conventional munitions, remain generations ahead of Russia’s.

Meanwhile, another problem that tactical nuclear weapons were designed to fix -- the inaccuracy of U.S. conventional bombs and missiles -- has also disappeared. For much of the Cold War, conventional weapons had such a large margin of error in their delivery that bombs had to be quite large in order to be certain of destroying their targets. But tactical nuclear weapons, with their impressive yields, were thought to be capable of getting practically any job done. (Not all shared this view; the U.S. Army distrusted the air force’s ability to destroy important bridges and so planned to have U.S. Special Forces use nuclear land mines for such contingencies instead.) But thanks to more accurate sensors and better information technology, today’s precision-guided bombs and missiles are far more effective than previous generations could have imagined, making a resort to tactical nuclear weapons unnecessary.

Analysts usually compare the effectiveness of various arms by measuring each weapon’s “probability of kill.” This metric is a function of a weapon’s accuracy and destructive power: the less accurate a weapon, the more power it needs to guarantee the destruction of a target. Tactical nuclear weapons are highly destructive, so even when relatively inaccurate, they still have a high probability of kill. Precision-guided munitions inflict far less damage but have greater accuracy, meaning that the average probability of kill of such weapons is comparable to that of a B-61. Even Russian President Vladimir Putin, who presides over an arsenal of some 3,000 tactical nuclear weapons, has come to grips with this reality, telling senior Russian officials last year, “The degree of precision and power of today’s high-precision weapons makes them essentially an alternative to nuclear weapons.”

Tactical nuclear weapons no longer offer any meaningful advantages over this new breed of conventional arms, and yet they still suffer from the same flaw they always did: the capacity for large-scale and indiscriminate destruction. Throughout the Cold War, exercises and war games routinely demonstrated these weapons’ potential for mass casualties. One NATO exercise in 1962 estimated that 10–15 million German civilians would be killed in a tactical nuclear exchange. An East German military study from the same period projected that such a war would expose an area the size of New York State (and over half the size of West Germany) to radiation levels high enough to cause poisoning in one hour and death in five. Given this drawback, tactical nuclear weapons would need to have demonstrable military advantages to justify their worth. But such advantages simply do not exist.

A KING’S RANSOM

Almost everybody agrees that tactical nuclear weapons lack military value. Those who wish to retain them argue that the bombs have political value and that failing to modernize this segment of NATO’s arsenal would signal a reduced U.S. commitment to the alliance. These arguments have gained strength in the wake of Russia’s interventions in Georgia in 2008 and, now, in Ukraine. Others have gone so far as to suggest that the removal of U.S. nuclear weapons from Europe could cause U.S. allies in Northeast Asia to doubt Washington’s reliability and seek to acquire nuclear arsenals of their own.

Unfortunately, the most recent statement of the U.S. government’s official nuclear policy -- the 2010 Nuclear Posture Review -- essentially adopts this misguided logic and commits the United States to modernizing its tactical nuclear weapons. Noting that Washington has already reduced its arsenal “dramatically,” the report tasks the air force with building a nuclear-capable F-35 to replace the aging F-16.

The review also notes that Washington remains “committed to making consensus decisions through NATO processes.” The problem with that promise is that European governments are deeply divided over whether or not they want to continue hosting U.S. bombs. In general, the weapons are deeply unpopular with European publics, and at the 2010 NATO summit, Belgium, Germany, Luxembourg, the Netherlands, and Norway joined together to call for the removal of U.S. tactical nuclear weapons from the continent. Last year, the Norwegian government hosted a conference to discuss the humanitarian consequences of nuclear war, an action interpreted by many as a rebuke to NATO policy. But many alliance members are of two minds. In 2009 and 2010, Germany’s and Poland’s defense ministers, for example, defended NATO’s tactical nuclear weapons at the same time as their foreign ministers were joining international coalitions to eliminate all nuclear weapons.

To be sure, the U.S. nuclear commitment to NATO remains a keystone of the alliance. Until the world has rid itself of nuclear weapons entirely, Washington needs to continue to assure its European allies that it will protect them from nuclear coercion or attack. But the credibility of such promises does not depend on a handful of tactical nuclear bombs and fighter planes.

What ultimately deters NATO’s foes are the United States’ substantial strategic nuclear forces: the long-range bombers, strategic submarines, and land-based intercontinental ballistic missiles (ICBMs) that are based in the United States and stand ready to deliver nearly 2,000 nuclear bombs and warheads within a matter of hours. Even a small portion of this force could devastate any nation foolish enough to test U.S. resolve. Although they are not located on European soil, these weapons provide the actual basis for the U.S. nuclear umbrella. The 65-year history of NATO and U.S.-European security cooperation provides evidence enough of Washington’s resolve; so long as the alliance holds, it does not matter whether the symbols of that commitment are B-61s in the Netherlands or ICBMs in North Dakota.

The U.S. military apparently agrees. According to a task force commissioned by the Pentagon in 2008 to review the Defense Department’s nuclear mission, U.S. European Command, or EUCOM, has given up its traditional role of advocating for maintaining nuclear weapons in Europe. EUCOM leaders told the task force that long-range nuclear forces in the United States were more cost effective than short-range weapons in Europe, that an “over the horizon” strategic capability was just as credible a deterrent, and that there would be “no military downside to the unilateral withdrawal of nuclear weapons from Europe.” The review quoted one senior U.S. defense official saying, “We pay a king’s ransom for these things and . . . they have no military value.”

Russia’s incursion into Ukraine has not changed this logic. In 2008, the United States could have defeated Russian forces in Georgia conventionally if Washington had so chosen. And neither conventional forces nor tactical nuclear weapons would have prevented the Russian subversion in Crimea. After all, Ukrainian forces did not lose; they did not fight. In any event, the presence of NATO's tactical nuclear weapons on the continent clearly has been irrelevant to decision-makers in Washington and Moscow. In fact, a full-fledged Russian invasion of Ukraine would only provide further proof that U.S. tactical nuclear weapons have no deterrent effect.

Washington’s European allies, moreover, are not entirely dependent on U.S. deterrence for their own security. Both France and the United Kingdom have nuclear-armed submarines, and the French have their own tactical nuclear bombs and the capability to deliver them. Although the U.S. commitment to NATO is credible enough to render these arsenals unnecessary, French and British warheads are two more reasons a potential aggressor would have to think twice before threatening a member of the alliance.

Conceding that the local case for maintaining tactical weapons in Europe is weak, other defenders of the status quo frame the issue as one of international credibility, claiming that Japan and South Korea, facing a near-term threat from North Korea and a rising challenge from China, are closely monitoring Washington’s commitment to its European allies, especially when it comes to nuclear deterrence. The United States thus has to continue underwriting tactical nuclear weapons in Europe, they claim, to reassure not only its European allies but also its Asian ones.

The flaw in this argument is that the United States no longer has nuclear weapons in Asia. Washington based nuclear weapons in Japan and South Korea for more than three decades but withdrew the last of them in 1991. If Washington truly feels it is necessary to use short-range fighters with nuclear bombs to assure its Asian allies, then it should redeploy nuclear weapons directly to Asia. Such a move would be unnecessary, since the United States can continue to protect its Asian allies with its strategic nuclear forces. But it would certainly have a more direct effect on leaders in Tokyo and Seoul -- not to mention Pyongyang -- than would retaining useless nuclear weapons in Europe.

In the recent past, the strongest argument in favor of keeping U.S. nuclear weapons in Europe centered on their potential as a bargaining chip with Russia. Although Washington has far fewer short-range systems than Moscow, the Kremlin has nonetheless long sought the removal of U.S. nuclear weapons from Europe, a fact that might increase the weapons’ negotiating value beyond their actual military worth. Phasing out tactical nuclear weapons unilaterally would mean forgoing the possibility of getting something from Moscow in return. But Russia’s recent incursion into Ukraine has put such a negotiation -- which was always a long shot -- ridiculously out of reach. As a result, the cost of maintaining such a bargaining chip far exceeds any value that could be gotten from trading it away at some distant point in the future.

A QUESTION OF VALUE

Doubts about the military value of tactical nuclear weapons are nothing new. Colin Powell favored abandoning them in the 1990s, when he was the chairman of the Joint Chiefs of Staff. Other prominent critics, such as Ivo Daalder, former U.S. ambassador to NATO, and Sir Malcolm Rifkind, a former British defense secretary and former foreign secretary, have long argued that the military rationale for keeping nuclear weapons in Europe is an anachronism.

But in the past, those doubts could always be overcome by arguments that the weapons might have some political value and that maintaining a small residual tactical nuclear force was relatively cheap and harmless. Today, that is no longer the case. In an era of fiscal austerity and declining defense budgets, the U.S. military faces stark tradeoffs. NATO allies in Europe face even more difficult choices. Investing in modernizing tactical nuclear weapons means not investing in other things that would undoubtedly have greater strategic value.

Under the discretionary spending caps locked in for the next seven years, all U.S. defense programs must compete against one another for survival. The bulk of the funding for modernizing the country’s tactical nuclear weapons resides with the Department of Energy’s National Nuclear Security Administration (NNSA). But it draws from the same discretionary spending pot that funds the Pentagon, so modernizing those weapons would come at the expense of other critical updates of the U.S. arsenal, including the development of a new long-range bomber and a new strategic submarine. It would also come at the expense of investments in the conventional capabilities that are the basis for U.S. security and have allowed Washington to provide crucial support for recent European-led operations, most notably in Libya and Mali.

Over the next decade, the NNSA plans to spend billions modernizing various nuclear warheads. The organization describes this project as an extension of an existing program, but its plans are in fact much more ambitious. The B-61 extension, for example, aims to fold four different warheads into a single design in order to improve their accuracy and reduce their explosive yield -- at a cost of at least $8 billion. The air force would also have to spend about $350 million to make the F-35 capable of carrying nuclear weapons and an additional $1.4 billion to allow the bomb to be guided when delivered by F-35 fighters or stealth B-2 bombers.

Some of this spending will remain necessary even if the United States does not modernize its tactical nuclear weapons, because a variant of the B-61 would still need to be carried by the most modern existing long-range bomber, the B-2, and the B-61 would need to have its own service life extended. But this program would incur a total cost of only around $2 billion, a far cry from the $10 billion or more required for a full modernization program.

For a sense of scale, consider that $10 billion represents the cost of more than ten years’ worth of flying time for all of the air force’s combat-enhancement forces -- including its surveillance, radar, and communications aircraft. So given the spending caps currently in place, the huge cost of modernizing U.S. nuclear weapons in Europe could easily come at the expense of flying time for the aircraft the United States actually uses in times of war and crisis. That prospect is an alarming one; the security of the United States and its European allies depends squarely on the experience of U.S. crews. In Libya in 2011 and Mali in 2013, it was U.S. aircraft, pilots, and operations officers -- not nuclear weapons -- that the Europeans were unable to do without.

Furthermore, modernizing the United States’ tactical nuclear weapons would entail large opportunity costs for the F-35 fighter program at a time when the program is already struggling to meet its many requirements. Integrating a nuclear weapons capability into the design of the F-35 would add hundreds of millions of dollars to its cost, require additional design studies and tests, and redirect time and funding away from developing the F-35’s more important conventional capabilities. Although the F-35 project involves several international partners, including some European allies, its primary customer remains the United States. Washington should not burden the program with additional and unnecessary requirements that have no military payoffs, at least not without major contributions from its European allies.

RETIREMENT PLAN

Instead of blindly absorbing the cost of modernizing its tactical nuclear systems, the United States should raise the prospect within NATO of permitting them to expire at the end of their planned service lives, roughly ten years from now. If the Europeans believe that maintaining nuclear weapons on the continent beyond that point is necessary, Washington should demand firm commitments from at least four of the allies to acquire and operate F-35 replacement aircraft capable of delivering rehabbed B-61 bombs. (The cost of providing the F-35 with a nuclear capability would have to be included in the cost of the aircraft.) The United States should also require NATO’s European members to contribute to the cost of extending the B-61’s service life. Payments could be prorated for the alliance members according to the sizes of their individual economies.

U.S. officials regularly complain that European countries do not spend enough on defense. Although Europe’s lack of spending mostly reflects its own fecklessness, Washington has done little to discourage free-riding, and the post–Cold War years of relative peace haven’t given the Europeans much reason to worry. Given how much the modernization of the U.S. tactical nuclear arsenal would cost, and given how little intrinsic value it has, undertaking such a project would essentially mean providing an additional, and unnecessary, defense subsidy to Europe, something that makes little sense. If the European members of NATO are truly unwilling to rely on U.S. conventional military superiority, backed up by the United States’ strategic nuclear deterrent, then they should be prepared to foot the bill for any modernized tactical nuclear force themselves.

If the Europeans do not wish to make such a political and financial commitment, the United States should make clear that its nuclear commitment to NATO (and to its Asian allies) remains firm but that it will phase out the tactical component of its nuclear arsenal over the next ten years. Sending that message would require two policy changes. First, the Pentagon would need to scrap its plans to make the F-35 nuclear capable and direct the resulting savings toward the high-priority program to develop a new conventional long-range bomber. This move would align with what Norton Schwartz, the former chief of staff of the U.S. Air Force, has already proposed. “Without financial buy-in by the NATO partners,” Schwartz told an audience at the Stimson Center last January, “F-35 investment dollars should realign to the long-range strike bomber.” Second, the NNSA would need to roll back the program to extend the B-61’s service life. Although some of those weapons would still have to be modernized for use on the B-2 long-range bomber, this move would yield considerable savings, perhaps as much as $8 billion.

To demonstrate its enduring commitment to NATO, meanwhile, Washington should continue to work closely with all its allies on joint force planning, war-gaming, and military exercises. More specifically, it should temporarily send long-range nuclear bombers, in conjunction with other forces, to European bases. In the late 1940s, such deployments helped strengthen Western resolve in the face of Soviet aggression. More recently, such actions have successfully calmed U.S. allies in Asia in the wake of North Korean provocations.

Skeptics might wonder how the United States would counter Russia’s tactical nuclear weapons without an arsenal of its own, but Russian arms should be of no concern. Over the next ten years, U.S. B-61s will remain in Europe. During that time, Washington can try to persuade Moscow to include tactical nuclear weapons in a new round of arms control negotiations or to reciprocally withdraw its nuclear weapons from operational bases in Europe. Such initiatives are unlikely to succeed in the near term; Moscow views U.S. tactical nuclear weapons as wasting assets and, as NATO did during the Cold War, now depends on its own tactical nuclear arsenal to compensate for its conventional inferiority. Eventually, however, Russian leaders could conclude that nuclear bluffs are poor substitutes for investing in conventional military capabilities. If they do not, Europe has little cause for worry: the more Moscow wastes its limited resources on useless weapons instead of investing in its increasingly lagging conventional capabilities, the better off Russia’s neighbors will be.

Some argue that even if U.S. tactical nuclear weapons are useless, Russia’s moves in Ukraine demand that their removal be delayed indefinitely. Yet maintaining the status quo is not an option. If Washington wants to retain its tactical nuclear weapons systems in Europe, the Pentagon will soon have to make a major long-term investment in their modernization. Squandering resources on outmoded weapons systems would be a poor way to confront Russia. Instead, Washington should step up other activities that can demonstrate U.S. resolve and abilities. Multilateral exercises in central Europe and temporary deployments of U.S. air and naval forces to allies in the Baltics and the Mediterranean are just two of the many ways that Washington could make clear that letting go of its tactical nuclear weapons in Europe is not a sign of retreat.

In any case, the United States’ nuclear doctrine makes clear that its strategic nuclear capabilities are intended to deter and, if necessary, respond to a nuclear attack on either the U.S. homeland itself or U.S. allies. It makes no difference whether the United States retaliates with tactical nuclear weapons or strategic ones. For decades, Washington has provided its allies in Europe with a credible nuclear deterrent, and it should continue to do so. But maintaining its tactical nuclear weapons in Europe is a particularly ineffective and wasteful way of keeping the continent safe.