EDITORIAL UPDATE, 3-16-22: a previous version of this blog noted there were eight more states that developed nuclear weapons and has been corrected to reflect the correct number which is seven.
In 1945, the United States—at the time the world’s only nuclear power—dropped two nuclear bombs on Hiroshima and Nagasaki, Japan. In the more than 75 years that followed, the United States and Soviet Union (USSR) engaged in a decades-long arms race, building tens of thousands of nuclear weapons and bringing the world to the brink of nuclear catastrophe thanks to multiple crises and repeated close calls due to human or computer error. Seven more states also developed nuclear weapons, but WWII remains the last time any state exploded a nuclear weapon in a conflict. This is even more notable since both the United States and the Soviet Union/Russia deployed shorter-range, lower-yield, tactical nuclear weapons and developed extensive plans—some of which still exist today—for their use in scenarios where they believed that they would be at a disadvantage in a conventional military conflict.
One explanation for this restraint is that countries developed a taboo against the use of nuclear weapons, coming to understand them as so horrific as to be essentially unusable except in the most extreme cases of last resort. But recent events—most notably Putin’s attempt to use nuclear threats to hold the world hostage as he wages war on Ukraine—are calling into question the future of this taboo. After all, a taboo can always be broken. In the end the best way to ensure that the world is safe from nuclear weapons is to eliminate them completely.
What is the “nuclear taboo”?
At the beginning of the atomic age, nuclear weapons, for all the devastation they caused in Japan, were expected to become just another weapon and to proliferate widely to any state that could develop them. There was much debate among political and military leaders about their usefulness as a deterrent, but also on the battlefield. And although President Truman established nearly from the beginning that in the United States nuclear weapons should be legally under presidential control, physical control of these weapons remained in military hands. Early on, before safeguards were established, this meant that it might have been possible for military leaders to use them without a presidential order. President Eisenhower, among others, also gave military commanders the authority to use nuclear weapons in urgent situations when they could not reach the president (this is sometimes called pre-delegation of authority).
Over time, however, nuclear weapons became a category separate from other kinds of weapons, and refraining from using nuclear weapons became a new norm of international behavior, what scholar Nina Tannenwald termed the “nuclear taboo.” Taboo here refers to “a particularly forceful kind of normative prohibition that is concerned with the protection of individuals and societies from behavior that is defined or perceived to be dangerous.”
Tannenwald says this taboo is “associated with a widespread revulsion toward nuclear weapons and broadly held inhibitions on their use.” She identifies the early and ongoing efforts of global grassroots antinuclear movements, nonnuclear weapon states, and nonstate actors like the United Nations—along with the eventual strategic nuclear stalemate between the US and USSR—as key in establishing the nuclear taboo by stigmatizing and delegitimizing the use of nuclear weapons.
How strong is the nuclear taboo?
When states maintain a clear line between nuclear and conventional weapons, reserving nuclear weapons solely for deterrence of nuclear attacks, they help to strengthen the nuclear taboo. Ideally this would mean states declaring that they will never use nuclear weapons first, and backing this up with a nuclear doctrine and force posture that does not include nuclear warfighting capabilities. Out of all the nuclear powers, only China has consistently taken this step, but even its long-standing commitment to a minimal nuclear force may now be coming into question.
Unfortunately, in recent years the trend seems to be toward weakening, rather than strengthening, the nuclear taboo. Russia and the United States, along with some other nuclear armed states, have placed greater emphasis on tactical nuclear weapons—shorter-range and often lower-yield nuclear weapons designed to be used on the battlefield. These are particularly destabilizing since they can be perceived as more “usable” than the strategic weapons carried by intercontinental submarine-launched ballistic missiles. When nuclear weapons are seen as tools of warfighting—such as using tactical nuclear weapons to counter conventional military threats—the unique danger of nuclear weapons is blurred, and the taboo is weakened.
Nuclear threats, such as Putin’s in Ukraine, also endanger the nuclear taboo. While they do not directly violate the taboo, they eat away at its foundation, raising doubts about its durability. Leaders who show a willingness to threaten nuclear use in any but the most dire of circumstances undermine the sense that nuclear weapons are so unthinkably abhorrent that their use should never be considered unless there is no question that the very existence of a state is in immediate danger.
The nuclear taboo is a norm, an unstated agreement on appropriate behavior that is strengthened by adherence over time but is not explicitly set out anywhere and is not in any way enforceable. A state that violates the taboo could face repercussions in the form of military action or economic sanctions. Or it could face social stigma that might have a less immediate impact, such as condemnation from other world leaders or censure at the United Nations. The consequences of breaking the nuclear taboo are, thankfully, so far unknown. But this means they are unknown not just to those who might break it, but also to those who must respond. Upholders of the taboo are left figuring out on the fly how to signal that such a violation will not go unpunished without further escalating a dangerous situation.
The nuclear taboo is not enough
While the nuclear taboo has helped to shift thinking on nuclear weapons, placing them outside of conventional warfare, ultimately it is not enough to ensure that these weapons will never be used. As we are observing right now with Putin’s loosely veiled threat that anyone interfering in his war on Ukraine will face “consequences they have never seen,” some leaders will always try to push the boundaries, which can weaken or undermine the taboo. Whether or not such leaders ever truly intend to follow through with these threats, their words raise the level of tension in an already volatile situation, increasing the likelihood of a miscalculation or miscommunication that could lead to actual nuclear conflict.
It is encouraging, and perhaps some evidence for the durability of the nuclear taboo, that the United States and others have shown restraint in the face of Putin’s threats, declining to raise their level of nuclear alert and, in the US case, postponing a ballistic missile test that could have been seen as provocative. But one can easily imagine a situation in which this were not the reaction. In 2017, in response to North Korea’s continued progress in its nuclear weapons program and Kim Jong Un’s threats against the United States, President Trump issued his own nuclear threat. Such a reaction—as irresponsible as it was at the time—could have a much larger and more unpredictable impact in the current situation.
Eliminating nuclear threats requires eliminating nuclear weapons
The only way to put an end to nuclear threats, and the catastrophic potential that they will be carried out, is to eliminate the weapons themselves. This may seem utopian but it is actually a long-recognized goal.
The Nuclear Nonproliferation Treaty (NPT) recognized this almost 50 years ago, and most of the world—including nuclear powers—signed on. One of the objectives of the NPT is nuclear disarmament, but the treaty allowed, under what was supposed to be a temporary basis, the existence of a handful of recognized nuclear weapon states (the United States, Russia, China, France, and the United Kingdom). In the treaty, those nuclear weapon states committed themselves to negotiate an end to the nuclear arms race with the goal of complete nuclear disarmament, to be enshrined in “a treaty on general and complete disarmament under strict and effective international control.” In exchange, the non-nuclear weapon states agreed not to pursue or acquire their own nuclear weapons.
The more recent Treaty on the Prohibition of Nuclear Weapons (TPNW) goes farther than the NPT, completely outlawing nuclear weapons on the way to eliminating them altogether. It aims to make the nuclear taboo international law. The TPNW has now been signed by 86 countries and ratified by 53; it entered into force on January 22, 2021. So far, none of the states that possess nuclear weapons have signed on. This is not surprising, since doing so would require them to commit to eliminating their nuclear arsenals by a specific date. But the treaty’s recognition that nuclear use would have consequences for people living far beyond nuclear weapon states and its outright prohibition on such weapons with no exceptions for existing nuclear weapon states are an affirmation of much of the world’s continuing commitment to maintaining the nuclear taboo.
Outside of treaties, some leaders, including US and Russian presidents, have also explicitly called for the abolition of nuclear weapons. After their two countries spent decades building up their nuclear arsenals and facing repeated crises and close calls, President Reagan and Russian President Mikhail Gorbachev in 1986 nearly reached an agreement to eliminate all nuclear weapons by the year 2000. Negotiations ultimately broke down over disagreement on ballistic missile defenses, but both leaders had already stated their beliefs that elimination was possible, and desirable. Neither man was a utopian idealist, they had simply both seen first-hand the dangers of nuclear brinkmanship and understood that as long as nuclear weapons exist, so does the risk that they will be used.
First end the current war, then prevent the next one
The war in Ukraine illustrates once again just how devastating even a conventional war is to the civilians who are caught up in its violence. The focus right now must be on preventing escalation, even if it does not reach the nuclear level, and ending Putin’s violence against the Ukrainian people.
But in the long run, the war in Ukraine demonstrates once again how nuclear weapons—even when they remain unexploded in the background—complicate conflicts. They raise the risk of escalation, intentional or mistaken, to an unimaginable level. Perhaps this most recent reminder can help serve as a catalyst to finally move towards the only real solution to the nuclear weapons problem—elimination.