No country has made military use of a nuclear bomb since the United States dropped the second one, on Nagasaki. “One of humanity’s remarkable achievements,” the conservative columnist George Will called it. But do we imagine that this pause will go on forever? There are signs that restraints on nuclear weapon use are weakening. If they fail, and a nuclear weapon is used, the universal realization will take hold that nuclear war is a fact of life. It will likely change the way the world works in ways that we will deeply regret. We need to develop an exit ramp from this predicament—to find a way to eliminate nuclear weapons. Yet to take this seriously is regarded by the political establishment and its hangers-on in academia and think tanks as a sign of extremism, or at least muddle-headedness. The subject hardly came up in the 2020 presidential election campaigns.

It’s easy to put nuclear weapons out of mind, to let sleeping dogs lie. The weapons play essentially no role in day-to-day life. Even Hollywood has given up making apocalyptic nuclear war movies.

But the nuclear weapons aren’t asleep. They are ready to go.

An officer carrying the “football”—a briefcase containing the nuclear codes—stays close to the US president at all times so he can launch nuclear weapons wherever he is. It has its ludicrous moments. A 2017 photo, for example, shows Presidents Trump and Xi Jinping and their wives entering a grand dinner in Beijing and, an awkward step behind them, the man with the football. But the seriousness is always there, as is the risk for millions, whether they know it or not. An incoming British prime minister, on the first day in office, writes handwritten letters of instructions to the captains of Britain’s four nuclear missile submarines on launch protocols if they lose touch with the government in a war. Do they launch their missiles, or just head for Canada? We don’t know. The letters are burned at the end of the prime minister’s term.

These arrangements in nuclear weapon countries are the pinnacles of decision chains that reach down to highly trained officers in bunkers sitting before consoles, ready to launch. In the United States those officers are probably doing their homework for a graduate course while they sit and wait. But if they—or their counterparts in eight other countries—get a valid order, they will turn the keys to close the firing circuits—and the world will never be the same.

The strategic experts seem convinced that since “deterrence” worked during the Cold War, it will keep working. So entrenched is this conventional thinking that no one is paying attention to the worldwide political and social changes that might well follow the next nuclear weapon use. Are the experts even right that it was “deterrence” that kept nuclear weapons leashed? Or were national leaders hesitant to use them in any case and to thereby open the gates to who-knows-what? Luck surely played a big part. There were some close calls.

Deterrence is made out to be so abstruse it can only be handled by nuclear sophisticates. A US Defense Department fact sheet says it requires “nuclear forces that are modern, robust, flexible, resilient, ready and appropriately tailored hedge against technological and other uncertainties and adapt to meet evolving threats.” (Is it plausible that US forces meet all these requirements?) But anyone who has experienced a rough schoolyard understands the basics. It’s convincing opponents not to harm you out of fear that, if they do, you will harm them more than they can stand. If your threatened retaliation is terrible enough, and convincing enough, it usually works. But not always. It’s all in the mind of the adversary. One thing is sure, it’s not algebra. Sometimes one side misjudges the situation, sometimes both do. Human beings are especially prone to do foolish things when under pressure. And crushing pressures are what national leaders and their advisors would surely experience in deciding on launching a nuclear attack, or on retaliating against a real or imagined one.

The dangers of poor judgment are compounded by the cult of toughness at high levels in government. In national security crises, prudence is often characterized as weakness, or even cowardice. It is an old problem: Thucydides wrote about it in his history of the Greek wars, but nuclear weapons have upped the stakes dramatically. Deterrence may appear reliable—until it is not. It’s been over a decade since the Schultz-Perry-Kissinger-Nunn quartet—all prominent former US statesmen—warned that “reliance on nuclear weapons for [deterrence] is becoming increasingly hazardous and decreasingly effective.” It is even more hazardous now.

An increasing belligerence. In the halls of power, 75 years since Hiroshima and Nagasaki, nuclear war has become an abstraction, stripped of its horrors. Nuclear-armed states flaunt their weapons to intimidate their foes. North Korea and the United States exchanged threats of annihilation. Pakistan and India have issued nuclear threats and counter threats. And how else can one interpret the President Trump’s threats to “obliterate” Iran? Or Israeli Prime Minister Netanyahu’s threat, during the 2016 ceremony for the latest German-built addition to Israel’s nuclear-armed submarine force, that Israeli submarines were “capable of striking in very great strength at all those who would harm [Israel].”

Another disquieting sign is the fading interest in “no-first-use” pledges—promises by a country that it will not use its nuclear weapons first in a conflict. Russia has withdrawn its earlier pledge, and China appears to be reconsidering its pledge. The United States, of course, never signed on.

Respect for the Non-Proliferation Treaty is diminishing as well. Consider the Saudi crown prince’s casual and brazen remark during a 2018 visit to the United States that he would immediately get nuclear weapons if Iran did. After learning what he is capable of, one could wonder whether he will even wait that long. In 2019, Turkish President Recep Tayyip Erdogan said it was “unacceptable” that Turkey is not permitted to have nuclear weapons when others have them. What he will do about this is unclear, but no leader of a Non-Proliferation Treaty member state that had pledged not to get nuclear weapons had ever publicly spoke this way before.

The threshold for using nuclear weapons is lowering in another way: the new deployment of “tactical” or battlefield nuclear weapons. Pakistan has introduced them to “deter” any Indian conventional attack. Pakistan seeks to make its nuclear threats more convincing by making them easier to carry out. In the same way, the United States has outfitted a ballistic missile submarine, with others to follow, with small warheads to plug a supposed deterrence gap—the possibility that an opponent, such as Russia, might imagine that the United States would be reluctant to use nuclear weapons in response to an attack with a small-yield nuclear weapon because US nuclear weapons had much larger yields.

The US Nuclear Posture Review. Current US policy on nuclear weapon use is laid out in the Defense Department’s 2018 Nuclear Posture Review. Both in substance and tone, the document leans significantly further toward nuclear weapon use than the previous 2010 version. To drive this home, the Defense Department published the summary in several languages, notably Russian and Chinese. What the Biden administration does with this document will tell the world a lot about its willingness to chart a safer course in nuclear policy.

The current document states the United States would use nuclear weapons only in “extreme circumstances,” but these turn out to be awfully broad: They include not only threats to the vital interests of the United States, but also to those of “its allies, and partners.” There are at least 35 European and Asian allies. The Defense Department says there are 76 “partners.” They can’t all be protected by US nuclear weapons, but which ones are? We don’t know. Does the Defense Department know?

If US leaders deem them significant enough, even conventional attacks against the United States and dozens of allies and partners can qualify as “extreme circumstances,” meriting a nuclear response. Moreover, the 2018 Nuclear Posture Review emphasizes that part of the US force is kept on alert to retain “the option of launching those forces promptly,” that is, launching on warning, perhaps even launching on warning of an impending attack, with the dangers of mistakes that attach to such a policy.

Part of the reason for this bluster is to support higher Air Force and Navy budgets. But there is another purpose. Having promised allies and partners a spot under America’s nuclear umbrella in return for a certain deference, the United States has to constantly shore up its credibility in the face of questions from allies and partners. The questions have become increasingly difficult to answer forthrightly as the United States has become overextended. It has led to American actions that don’t necessarily make military or political sense but are expected by allies. Consider the Nuclear Posture Review’s reason for why the United States has to provide allies with nuclear protection even against conventional attack: “Conventional forces alone are inadequate to assure many allies who rightly place enormous value on US extended deterrence for their security” (emphasis mine). The tail is wagging the dog—a dangerous business.

The official Russian and semiofficial Chinese views. Following a 2020 executive order from President Putin, Russia also published its policy on nuclear weapons use. Russia asserts the right to use nuclear weapons to defend Russia and its allies against both nuclear and conventional attacks, including impending missile attacks, which Russia will assume to be nuclear. Conventional attacks in this category include those that would undermine the functioning of Russia’s nuclear forces. These conditions more or less parallel those of the United States as presented in the Nuclear Posture Review, but they are more circumscribed: Russia provides nuclear protection for fewer allies—several former Soviet republics on Russia’s borders. And Russia restricts nuclear weapon use against conventional attacks to situations “when the very existence of the state is in jeopardy,” which sounds tighter than the Nuclear Posture Review’s “extreme circumstances,” although it is hard to say what the difference would really amount to if push came to shove. Regardless, the world’s two major nuclear protagonists have laid out expansive conditions for using their nuclear arsenals and, if anything, are increasing emphasis on nuclear weapons’ central role in their national security policies.

China is the other important nuclear power. Its leaders have not released an official statement on nuclear weapons use comparable to the US or Russian documents, but a semi-official account by a retired general suggests China is placing greater emphasis on its nuclear forces and rethinking its declared no-first-use policy. It argues it has to “face the reality” that other nuclear weapon states are “planning huge investments to modernize their nuclear arsenals and to prepare to fight a nuclear war. . . The long-held theory of the nuclear taboo is increasingly on the verge of being broken.” Can we say this is completely off the mark?

Can we keep it up? It is difficult to believe that, with all the expensive nuclear weaponry the United States and others have and are modernizing, the world’s nuclear-armed countries will indefinitely confine their nuclear forces to conducting exercises and simulating nuclear exchanges on computers. There are too many clever young strategists dreaming up new ways to squeeze a little more political advantage from possession of nuclear weapons or from threats to build them. And it would be foolish to imagine that everyone in the nuclear weapon supply chain really wants the bombs never to get used; it contradicts human nature to devote one’s life to developing a technology and hope it is never used. There are many checks, of course, to prevent illicit use and accidental explosions, but it is hard to maintain proper discipline and motivation in a system that is never used for its intended purpose.

Ronald Reagan, who wasn’t exactly a Ban-the-Bomb marcher, didn’t think we could go on this way. He said of the US–Soviet standoff: “I can’t believe that this world can go on beyond our generation and on down to succeeding generations with this kind of weapon on both sides poised at each other without someday some fool or some maniac or some accident triggering the kind of war that is the end of the line for all of us.” In one of his last messages to Congress, he said his aim was to eliminate the bomb.

In the 30 years since then, it has remained clear that many in the US nuclear weapons world don’t share this goal with President Reagan, even if it gets occasional lip service. The political-military establishment imagines it can hang on to these weapons permanently. The same appears true in the other eight nuclear-weapon-possessing countries. Change can come—if at all—only if forced by massive worldwide public pressure.

The fear of losing control of nuclear weapons policy explains the State Department’s almost hysterical reaction to the proposed Treaty on the Prohibition of Nuclear Weapons, which will enter into force in January 2021. As all nuclear weapon states and their allies, including all NATO countries, rejected the ban treaty, its only foreseeable practical effect could be to provoke worldwide discussion on eliminating nuclear weapons. Even this apparently was too threatening to things-as-they-are. US Assistant Secretary of State Christopher Ford wrote that the treaty “is likely to make real disarmament progress harder, not easier, by poisoning and undermining the cooperative dialogue the world needs” to get to nuclear weapons elimination (my emphasis). Never mind that the world is every day getting further from nuclear weapons elimination.

Whether the Biden administration will take a different approach is unclear. It would take an unusual openness to new ideas on the part of incoming officials, and the political courage to accept plain truths, but it can happen. Paul Nitze, probably the most hawkish architect of US Cold War nuclear strategy, modified his views in his later years as President Ronald Reagan’s Special Advisor on Arms Control. In a 1999 New York Times op-ed, he wrote, “I know that the simplest and most direct answer to the problem of nuclear weapons has always been their complete elimination. … It is the presence of nuclear weapons that threatens our existence.”