It is time for the U.S. government to admit that it has failed to prevent North Korea from acquiring nuclear weapons and intercontinental ballistic missiles that can reach the United States. North Korea no longer poses a nonproliferation problem; it poses a nuclear deterrence problem. The gravest danger now is that North Korea, South Korea, and the United States will stumble into a catastrophic war that none of them wants.

The world has traveled down this perilous path before. In 1950, the Truman administration contemplated a preventive strike to keep the Soviet Union from acquiring nuclear weapons but decided that the resulting conflict would resemble World War II in scope and that containment and deterrence were better options. In the 1960s, the Kennedy administration feared that Chinese leader Mao Zedong was mentally unstable and proposed a joint strike against the nascent Chinese nuclear program to the Soviets. (Moscow rejected the idea.) Ultimately, the United States learned to live with a nuclear Russia and a nuclear China. It can now learn to live with a nuclear North Korea.

Doing so will not be risk free, however. Accidents, misperceptions, and volatile leaders could all too easily cause disaster. The Cold War offers important lessons in how to reduce these risks by practicing containment and deterrence wisely. But officials in the Pentagon and the White House face a new and unprecedented challenge: they must deter North Korean leader Kim Jong Un while also preventing U.S. President Donald Trump from bumbling into war. U.S. military leaders should make plain to their political superiors and the American public that any U.S. first strike on North Korea would result in a devastating loss of American and South Korean lives. And civilian leaders must convince Kim that the United States will not attempt to overthrow his regime unless he begins a war. If the U.S. civilian and military leaderships perform these tasks well, the same approach that prevented nuclear catastrophe during the Cold War can deter Pyongyang until the day that communist North Korea, like the Soviet Union before it, collapses under its own weight.

DANGER OF DEATH

The international relations scholar Robert Litwak has described the current standoff with North Korea as “the Cuban missile crisis in slow motion,” and several pundits, politicians, and academics have repeated that analogy. But the current Korean missile crisis is even more dangerous than the Cuban one. For one thing, the Cuban missile crisis did not involve a new country becoming a nuclear power. In 1962, the Soviet Union was covertly stationing missiles and nuclear warheads in Cuba when U.S. intelligence discovered the operation. During the resulting crisis, Cuban Prime Minister Fidel Castro feared an imminent U.S. air strike and invasion and wrote to Soviet Premier Nikita Khrushchev advocating a nuclear strike on the United States “to eliminate such danger forever through an act of clear legitimate defense, however harsh and terrible the solution would be.” When Khrushchev received the message, he told a meeting of his senior leadership, “This is insane; Fidel wants to drag us into the grave with him!” Luckily, the Soviet Union maintained control of its nuclear weapons, and Castro did not possess any of his own; his itchy fingers were not on the nuclear trigger.

Kim, in contrast, already presides over an arsenal that U.S. intelligence agencies believe contains as many as 60 nuclear warheads. Some uncertainty still exists about whether North Korea can successfully mount those weapons on a missile capable of hitting the continental United States, but history cautions against wishful thinking. The window of opportunity for a successful U.S. attack to stop the North Korean nuclear program has closed.

At the time of the Cuban missile crisis, both the American and the Soviet nuclear war plans were heavily geared toward preemption. Each country’s system featured a built-in option to launch nuclear weapons if officials believed that an enemy attack was imminent and unavoidable. This produced a danger that the strategist Thomas Schelling called “the reciprocal fear of surprise attack.” That fear was why Khrushchev was so alarmed when a U.S. U-2 spy plane accidentally flew into Soviet airspace during the crisis. As he wrote to U.S. President John F. Kennedy on the final day of the crisis: “Is it not a fact that an intruding American plane could be easily taken for a nuclear bomber, which might push us to a fateful step?” Today, the world faces an even more complex and dangerous problem: a three-way fear of surprise attack. North Korea, South Korea, and the United States are all poised to launch preemptive strikes. In such an unstable situation, the risk that an accident, a false warning, or a misperceived military exercise could lead to a war is alarmingly high.

The same approach that prevented nuclear catastrophe during the Cold War can deter Pyongyang.

Another factor that makes today’s situation more dangerous than the Cuban missile crisis is the leaders involved. In 1962, the standoff included one volatile leader, Castro, who held radical misperceptions of the consequences of a nuclear war and surrounded himself with yes men. Today, there are two such unpredictable and ill-informed leaders: Kim and Trump. Both men are rational and ruthless. Yet both are also prone to lash out impulsively at perceived enemies, a tendency that can lead to reckless rhetoric and behavior.

This danger is compounded because their senior advisers are in a poor position to speak truth to power. Kim clearly tolerates no dissent; he has reportedly executed family members and rivals for offering insufficiently enthusiastic praise. For his part, Trump often ignores, ridicules, or fires those who disagree with him. In May, The New York Times reported that Trump had described his national security adviser, Lieutenant General H. R. McMaster, as “a pain” for subtly correcting him when he made inaccurate points in meetings. And in June, the spectacle of U.S. department secretaries falling over themselves to declare their deep devotion to Trump and flatter him on live television during the administration’s first full cabinet meeting brought to mind the dysfunctional decision-making in dictatorships. Any leader who disdains expertise and demands submission and total loyalty from his advisers, whether in a democracy or in a dictatorship, will not receive candid assessments of alternative courses of action during a crisis.

President John F. Kennedy signs a proclamation for the interdiction of the delivery of offensive weapons to Cuba during the Cuban missile crisis, October 1962 Cecil Stoughton / John F. Kennedy Presidential Library / REUTERS

TONE-DEFCON

Trump’s poor decision-making process highlights another disturbing contrast with the Cuban missile crisis. In 1962, strong civilian leaders countered the U.S. military’s dangerously hawkish instincts. When the Joint Chiefs of Staff recommended an immediate air strike and an invasion of Cuba, Kennedy insisted on the more prudent option of a naval blockade. Together with his subsequent refusal to retaliate with an air strike after an American U-2 spy plane was shot down over Cuba, Kennedy’s approach reflected the best kind of cautious crisis management.

Now, however, it is the senior political leadership in the United States that has made reckless threats, and it has fallen to Secretary of Defense James Mattis (a former general) and senior military officers to serve as the voices of prudence. In early August, Trump warned: “North Korea best not make any more threats to the United States. They will be met with fire and fury like the world has never seen.” By appearing to commit to using nuclear force in response to North Korean threats, he broke sharply with U.S. deterrence policy, which had previously warned of military responses only to acts of aggression. Vice President Mike Pence, Secretary of State Rex Tillerson, and UN Ambassador Nikki Haley have not echoed Trump’s “fire and fury” rhetoric, but they have repeated the worrying mantra that “all options are on the table.”

That phrase may sound less threatening than Trump’s comments, but it still leaves itself open to misinterpretation. To some listeners, it just suggests that Washington is considering limited military options. But from a North Korean perspective, the statement implies that the United States is contemplating launching a nuclear first strike. This would not be an altogether unreasonable conclusion for Pyongyang to draw. In 2008, U.S. President George W. Bush stated that all options were on the table when it came to U.S. tensions with Iran, and when a reporter explicitly asked Bush whether that included “nuclear options,” Bush simply repeated himself: “All options are on the table.” The Obama administration made a commitment, in its 2009 Nuclear Posture Review, not to use nuclear weapons against any non-nuclearweapons state that was in compliance with its nonproliferation commitments. But then Secretary of Defense Robert Gates quickly added that “because North Korea and Iran are not in compliance with the Nuclear Nonproliferation Treaty, for them, all bets are off. All options are on the table.”

Such rhetoric is dangerous. The U.S. government must convince Kim that an attack on the United States or its allies would spell the end of his regime. But it is equally important that U.S. leaders acknowledge loudly and often that it would be a disaster for the United States to start a war. If those in the White House do not do so, the civilian and military leadership in the Pentagon should more forcefully and publicly make this point.

To back this rhetoric up, the United States should take some military options off the table, starting with a preventive nuclear war. A preemptive strike, the use of force when a country considers an adversary’s first strike imminent and unavoidable, can sometimes be justified strategically and legally as “anticipatory self-defense.” But preventive war—starting a war to prevent another country from taking future action or acquiring a dangerous capability—is rarely justified and arguably contrary to the UN Charter.

U.S. military officers are trained to follow orders from political authorities, unless they are clearly unconstitutional. The Constitution, however, says nothing about what to do if a president’s orders are legal but also crazy. This leads to bizarre situations, such as the response that Admiral Scott Swift, the commander of the U.S. Pacific Fleet, gave when he was asked at a seminar at the Australian National University in July if he would launch a nuclear strike against China “next week” if Trump ordered him to do so. The admiral should have said that the hypothetical scenario was ridiculous and left it at that. Instead, he answered, “Yes.”

The current Korean missile crisis is even more dangerous than the Cuban one.

Trump’s volatility has produced a hidden crisis in U.S. civil-military relations. In 1974, during the final days of Richard Nixon’s presidency, when Nixon had become morose and possibly unstable, Secretary of Defense James Schlesinger told the chairman of the Joint Chiefs of Staff, General George Brown, that if Nixon gave military orders, Brown should contact Schlesinger before carrying them out. Schlesinger’s action was extraconstitutional but nonetheless wise, given the extraordinary circumstances. The U.S. government faces similar dangers every day under Trump. Mattis and senior military leaders should be prepared to ignore belligerent tweets, push back against imprudent policies, and resist any orders that they believe reflect impetuous or irrational decision-making by the president. Their oath, after all, is not to an individual president; it is to “support and defend the Constitution of the United States.” The Constitution’s 25th Amendment lays out procedures on how to relieve an impaired president of his responsibilities. If senior military leaders believe at any time that Trump is impaired, they have a duty to contact Mattis, who should then call for an emergency cabinet meeting to determine whether Trump is “unable to discharge the powers and duties of his office” and thus whether to invoke the 25th Amendment.

WHAT YOU DON’T KNOW CAN HURT YOU

One similarity with the Cuban missile crisis is that those Americans who think the United States should attack North Korea exaggerate the prospects that U.S. military action would succeed and underestimate the costs of a war. In 1962, the CIA and the military assumed that there were no nuclear weapons in Cuba and, on that basis, recommended air strikes and an invasion. But the intelligence assessment was wrong. Well over 60 nuclear warheads, gravity bombs, and tactical nuclear weapons had already arrived in Cuba, and one missile regiment was already operational by the time the Joint Chiefs were advising military action. Any attack on Cuba would almost certainly have led to nuclear strikes on the United States and against invading U.S. forces.

Today, U.S. intelligence finds itself once again in the dark. It does not know the status of North Korea’s warheads or the locations of its missiles. For example, when the North Koreans successfully tested an intercontinental ballistic missile in late July, it came as a complete surprise to the United States and demonstrated that North Korea can now build such missiles, store them, take them out of storage, and launch them, all before the United States could react. Yet U.S. military leaders have failed to pour cold water on the idea of a U.S. first strike. Instead, they have added fuel to the fire.

Consider the complaint expressed by General Joseph Dunford, the chairman of the Joint Chiefs of Staff, at the Aspen Security Forum in July that “many people have talked about the military options with words such as ‘unimaginable.’” Dunford insisted that, to the contrary, “it is not unimaginable to have military options to respond to North Korean nuclear capability. What’s unimaginable to me is allowing a capability that would allow a nuclear weapon to land in Denver, Colorado.... And so my job will be to develop military options to make sure that doesn’t happen.” Dunford should have reinforced deterrence. Instead, he created a redline that Kim may have already crossed.

The military’s job is to come up with options. That involves thinking the unthinkable. But it is also military leaders’ responsibility to offer brutal honesty to political leaders and the public. When it comes to the current conflict with North Korea, that means admitting that there are no military options that do not risk starting the most destructive war since 1945.

South Korean marines during a U.S.-South Korean exercise, Pohang, South Korea, April 2017 Kim Hong-Ji / REUTERS

WHY THERE’S NO MILITARY SOLUTION

Some Trump supporters, including former UN Ambassador John Bolton and Trump’s evangelical adviser Robert Jeffress, have argued that a U.S. strike to assassinate Kim is the best solution. Any attempt to “decapitate” the regime, however, would be a gamble of epic proportions. The history of unsuccessful U.S. decapitation attempts, including those launched against the Libyan leader Muammar al-Qaddafi in 1986 and the Iraqi leader Saddam Hussein in 1991 and again in 2003, warns against such thinking. Moreover, Kim may well have ordered his generals to launch all available weapons of mass destruction at the enemy if he is killed in a first strike—as did Saddam before the 1990–91 Gulf War. There is no reason to think that the North Korean military would fail to carry out such an order.

U.S. leaders should also resist the temptation to hope that limited, or “surgical,” conventional attacks on North Korean missile test sites or storage facilities would end the nuclear threat. Proponents of this course believe that the threat of further escalation by the United States would deter North Korea from responding militarily to a limited first strike. But as the political scientist Barry Posen has explained, this argument is logically inconsistent: Kim cannot be both so irrational that he cannot be deterred in general and so rational that he could be deterred after having been attacked by the United States. Moreover, even a limited attack by the United States would appear to North Korea as the beginning of an invasion. And because no first strike could destroy every North Korean missile and nuclear weapon, the United States and its allies would always face the prospect of nuclear retaliation.

Mattis and senior military leaders should be prepared to resist any orders that they believe reflect impetuous or irrational decision-making by the president.

Nor can missile defense systems solve the problem. The United States should continue to develop and deploy missile defenses because they complicate North Korean military planning, and any missiles that Pyongyang aims at U.S. or allied military targets are missiles not aimed at American, Japanese, or South Korean cities. But military leaders should be candid about the limits of U.S. ballistic missile defenses. Most such systems have failed numerous tests, and even the most effective ones, such as the Terminal High Altitude Area Defense, or THAAD, system, could be overwhelmed if North Korea fired multiple missiles—even dummy missiles—in a salvo at one target. That is why North Korea has been practicing launching several missiles simultaneously. Any prudent U.S. planner should therefore assume that in the event of an attack, some North Korean nuclear-armed missiles would reach their targets. Even in the best-case scenario, in which only a few North Korean nuclear weapons penetrated U.S. defenses, the consequences would prove catastrophic.

Estimating the potential fatalities in a limited nuclear strike is difficult, but the nuclear weapons scholar Alex Wellerstein has designed a useful modeling tool called NUKEMAP, which uses data from the Hiroshima and Nagasaki bombings to provide rough estimates of how many people would die in a nuclear strike. After North Korea conducted its sixth nuclear test, in early September, Japanese, South Korean, and U.S. intelligence agencies reportedly provided a range of estimates of the weapon’s explosive yield, with an average estimate of around 100 kilotons. According to NUKEMAP, a single 100-kiloton nuclear weapon detonated above the port city of Busan, in South Korea (which was shown as a target in a recent North Korean press release), would kill 440,000 people in seconds. A weapon of that size detonated over Seoul would kill 362,000; over San Francisco, the number would be 323,000. These estimates, moreover, include only immediate blast fatalities, not the deaths from fires after a nuclear detonation or the longer-term deaths that would result from radioactive fallout. Those secondary effects could easily cause the number of dead to double.

Even if a war were limited to the Korean Peninsula, the costs would still be unacceptable. According to a detailed study published in 2012 by the Nautilus Institute, a think tank based in California, North Korea has thousands of conventional artillery pieces along the demilitarized zone that by themselves could inflict some 64,000 fatalities in Seoul on the first day of a war. A major attack on South Korea could also kill many of the roughly 154,000 American civilians and 28,000 U.S. service members living there. If the North Korean regime used its large arsenal of chemical and biological weapons, the fatalities would be even higher. Finally, there are a number of nuclear power plants near Busan that could be damaged, spreading radioactive materials, in an attack. All told, one million people could die on the first day of a second Korean war.

A military drill in North Korea, March 2016 KCNA

ACCIDENTAL WAR

Even if the United States forswore preventive conventional or nuclear strikes, the danger of an accidental war caused by the mutual fear of a surprise attack would remain. South Korea increasingly (and quite openly) relies on a strategy of preemption and decapitation. In 2013, General Jeong Seung-jo, the chairman of the South Korean Joint Chiefs of Staff, announced that “if there is a clear intent that North Korea is about to use a nuclear weapon, we will eliminate it first even at the risk of a war,” adding that “a preemptive attack against the North trying to use nuclear weapons does not require consultation with the United States and it is the right of self-defense.” A white paper published by the South Korean Ministry of National Defense in 2016 featured an illustration of several missiles being fired at and a group of South Korean commandos attacking the “war command” building in Pyongyang. (Unsurprisingly, the North Koreans have similar ideas about preemption: in April 2016, in response to U.S. and South Korean military exercises, North Korean state media reported that “the revolutionary armed forces of [North Korea] decided to take preemptive attack as the mode of its military counteraction.... The right to nuclear preemptive attack is by no means the U.S. monopoly.”)

Reducing the risk of war will require an end to U.S. threats of first-strike regime change.

In such a tense environment, one government’s preemptive-war plan can look a lot like a first-strike plan to its enemies. Would Seoul see the movement of Pyongyang’s nuclear missiles out of the caves in which they are stored as a drill, a defensive precaution, or the start of an attack? Would Pyongyang mistake a joint U.S.–South Korean exercise simulating a decapitation attack for the real thing? Could an ill-timed inflammatory tweet by Trump provoke a military response from Kim? What if a radar technician accidentally put a training tape of a missile launch into a radar warning system—which actually happened, creating a brief moment of panic, during the Cuban missile crisis? Add in the possibility of an American or a South Korean military aircraft accidentally entering North Korean airspace, or a North Korean nuclear weapon accidentally detonating during transport, and the situation resembles less a Cuban missile crisis in slow motion than an August 1914 crisis at the speed of Twitter.

The fear of a U.S. attack explains why Kim believes he needs a nuclear arsenal. Pyongyang’s nuclear weapons development undoubtedly appeals to Kim’s domestic audience’s desire for self-sufficiency. But that is not its primary purpose. Kim’s spokespeople have stressed that he will not suffer the fate of Saddam or Qaddafi, both of whom gave up their nuclear programs only to be attacked later by the United States. The North Korean nuclear arsenal is not a bargaining chip. It is a potent deterrent designed to prevent a U.S. attack or disrupt one that does occur by destroying U.S. air bases and ports through preemption, if possible, but in retaliation if necessary. And if all else fails, it is a means for exacting revenge by destroying Kim’s enemies’ cities. That may sound implausible, but keep in mind that Castro recommended just such an attack in 1962.

KEEP CALM AND DETER ON

Living with a nuclear North Korea does not, in Dr. Strangelove’s terms, mean learning “to stop worrying and love the bomb.” On the contrary, it means constantly worrying and addressing every risk. U.S. policy should aim to convince Kim that starting a war would lead to an unmitigated disaster for North Korea, especially as his own ministers and military advisers may be too frightened of his wrath to make that argument themselves. The United States should state clearly and calmly that any attack by North Korea would lead to the swift and violent end of the Kim regime.

Kim may be under the illusion that if North Korea were to destroy U.S. air bases and kill hundreds of thousands of Americans, Japanese, and South Koreans, the American public would seek peace. In fact, it would likely demand vengeance and an end to Kim’s regime, regardless of the costs. Such a war would be bloody, but there is no doubt which side would prevail. There are few, if any, military targets in North Korea that the United States could not destroy with advanced conventional weapons in a long war. And the Kim regime cannot ignore the possibility of U.S. nuclear retaliation.

The more difficult challenge will be convincing Kim that the United States will not attack him first. Reducing the risk of war will therefore require an end to U.S. threats of first-strike regime change. In August, Tillerson told reporters that the United States did not seek to overthrow Kim unless he were to begin a war. Other American leaders should consistently echo Tillerson’s comments. Unfortunately, the Trump administration’s rhetoric has been anything but consistent.

Should the United States succeed in bringing North Korea back to the negotiating table, it should be prepared to offer changes to U.S. and South Korean military exercises in exchange for limits on—and notifications of—North Korean missile tests and the restoration of the hotline between North and South Korea. The United States should also continue to extend its nuclear umbrella to South Korea to reduce the incentive for Seoul to acquire its own nuclear arsenal. Some have argued for a return of U.S. tactical nuclear weapons to air bases in South Korea, but such weapons would be vulnerable to a North Korean first strike. A better option would be to keep nuclear capable bombers at Guam on ground alert. Or the United States could borrow a tactic it used in the wake of the Cuban missile crisis. To assuage Moscow, Washington promised to remove its Jupiter ballistic missiles from Turkey after the crisis. But to reassure Ankara, it also assigned some submarine-based missiles to cover the same retaliatory targets in the Soviet Union that the Jupiter missiles had and arranged for a U.S. submarine to visit a Turkish port. Today, occasional U.S. submarine calls at South Korean harbors could enhance deterrence without provoking North Korea.

In 1947, the American diplomat George Kennan outlined a strategy for the “patient but firm and vigilant containment” of the Soviet Union. Writing in this magazine, he predicted that such a policy would eventually lead to “either the breakup or the gradual mellowing of Soviet power.” He was right. In the same way, the United States has deterred North Korea from invading South Korea or attacking Japan for over 60 years. Despite all the bluster and tension today, there is no reason why Kennan’s strategy of containment and deterrence cannot continue to work on North Korea, as it did on the Soviet Union. The United States must wait with patience and vigilance until the Kim regime collapses under the weight of its own economic and political weakness.