Trump and Kim in Singapore, June 2018.

At the United Nations this week, U.S. President Donald Trump smilingly teased another summit to discuss nuclear weapons with North Korean leader Kim Jong Un and then angrily denounced reports that he had sought a similar meeting with Iranian President Hassan Rouhani. The disparity reflected Trump’s personalist approach to nuclear weapons: he rejects any policy associated with his predecessor while embracing those leaders who flatter his sense of himself as a supreme dealmaker. On substance alone, it’s impossible to understand the decision to reject the Iran nuclear deal, known as the Joint Comprehensive Plan of Action, as “the worst deal ever” while embracing a denuclearization process with North Korea that imposes no requirements at all. But if Trump is prioritizing his feelings over his policy preferences, the two actions make sense. 

A personalist approach to diplomacy that goes case by case is not necessarily a bad one. What works in one situation may not work in another. But when it comes to global efforts to control the spread of nuclear weapons, the double standard inherent in Trump’s approach presents a mortal threat. Nonproliferation diplomacy requires sustained cooperation among all the significant powers, even when, in a particular case, their narrow interests do not align. Making exceptions undermines the very enterprise of setting aside narrow interests in support of broader ones, and leaves open the interpretation that the United States sees nonproliferation efforts as little more than politics by other means.

U.S. diplomats have long struggled to persuade China, Russia, and other countries that U.S. concerns about proliferation aren’t really about regime change. Although this has been an uphill battle, the strong sanctions placed on Iran before the JCPOA and those imposed on North Korea today show the value of sustained diplomacy. Now Trump has dismissed all that as a sham, throwing out one carefully negotiated agreement and declaring another problem solved after a single summit. It’s unlikely that China and Russia will ever enforce future sanctions on either Iran or North Korea with anything close to the effort seen in recent years. The result may even be a broader collapse of support for U.S.-led efforts to stop the spread of the bomb.


Five states had used or tested nuclear weapons, and India and China had nuclear programs well underway, before the international community reached a consensus that the spread of nuclear weapons was a bad thing.The initial view in the United States, as well as in the Soviet Union, was that the spread of nuclear weapons was, by itself, neither good nor bad. It was good when one’s allies did it but bad when one’s enemies did. The problem was that in a bipolar world, most important countries were allied to one bloc or the other.

This led to a nagging sense that the spread of nuclear weapons was uncontrollable, a fear that turned to panic after Mao Zedong’s China tested a nuclear weapon in 1964. China’s achievement also prompted a second realization. Although the Soviet Union had provided an essential boost at the beginning of the Chinese nuclear program, Beijing completed its bomb even after the Soviet Union withdrew its assistance and even despite the tremendous dislocation that followed the Great Leap Forward. U.S.and Soviet policymakers began to realize that, even without their cooperation, anyone who wanted a nuclear bomb could make one. In the United States, a commission led by the former defense department official Roswell Gilpatric suggested in 1965 that the United States and the Soviet Union shared an interest in working together to control the spread of nuclear weapons, instead of encouraging their allies to proliferate. 

The result of that shared interest was that the United States, the Soviet Union, and many other countries agreed to the Nuclear Nonproliferation Treaty (NPT), which entered into force in 1970. Of course, not everyone was impressed. Plenty of states, including India and Israel, refused to sign. When U.S. President Richard Nixon decided to seek ratification of the agreement in the Senate, he explicitly stated, “There should be no effort by the U.S. Government to pressure other nations, in particular [West] Germany, to follow suit.” China and France refused to join until the 1990s. Yet the moment marked a historical pivot. When the treaty came up for review in 1995, the United States led a successful effort to extend it indefinitely.

Today, things are both better and worse. The bad news is that building the bomb has never been easier. North Korea—no one’s idea of a technological powerhouse—has been able to test a thermonuclear weapon and an ICBM that could carry it all the way to the continental United States despite strong international sanctions. Iran, too, faces no serious technological constraint to building either nuclear weapons or very long-range missiles if it chose to do so. The kinds of underlying technologies that were out of reach to would-be proliferators in the past—computer controlled machine tools, optical fiber cables, integrated circuits—are now commonplace.

The good news, though, is that there has never been a stronger sense that nuclear weapons are reprehensible. As coercive tools have become less effective, the soft power of persuasion has grown. Fuzzy norms are perhaps not quite as macho as sanctions and the threat of fire and fury, but there is a growing sense that nuclear weapons are abhorrent. In 1963, U.S. President John F. Kennedy famously warned that 20 or 25 countries might build nuclear weapons by 1970. That future did not come to pass, in large part because of changing attitudes. The list of future nuclear powers that the CIA gave to Kennedy is now declassified. The document is revealing, because those 20 to 25 countries weren’t the Irans or North Koreas of the world but countries such as Australia and Sweden. Before the NPT, the expectation was that any country that could build a bomb probably would. Today, we don’t have to worry about nuclear weapons programs in rich Western countries. Most people have forgotten those programs even existed. But instead of being grateful for the norm against proliferation, U.S.policymakers hate the nuclear weapons ban, seeing it as little more than an attack on U.S. extended deterrence. That’s because they still look at opposition to nuclear weapons through the lens of protests against the deployment of U.S. nuclear weapons to Europe during the early 1980s. They don’t appreciate today's sincere international opposition to nuclear weapons and don’t understand how to mobilize it to support a core U.S. interest, nonproliferation.


There has long been a nagging sense around the world that U.S. emphasis on nonproliferation is insincere. After all, the U.S.officials who advocated invading Iraq to stop a nuclear weapons program that did not exist and now complain wildly about Iran’s nuclear weapons program are happy to ignore Israel’s nuclear arsenal. Those same officials also argued for carving out an exception for India despite its refusal to sign the NPT. And many critics point out that Libyan dictator Muammar al-Qaddafi abandoned his nuclear weapons program in exchange for what he believed to be British and U.S. security guarantees, only to be toppled with the support of British and U.S. airpower.

It’s possible to rationalize each of these cases. India and Israel were already de facto nuclear powers at the time of the NPT and refused to sign it. That’s rather different than North Korea and Iran today. And Qaddafi could probably never have finished building the bomb, so why promise him immunity for murdering protestors, many ask. These inconsistencies have not in any case altered the general sense that responsible countries, such as Japan and South Korea, should not acquire nuclear weapons—and that if they made any attempt to do so, the result would be international isolation. 

At least, that understanding held until Trump came along. On the campaign trail, Trump frequently made comments suggesting that it would not be such a bad thing if Japan or South Korea built an atomic bomb. This was mostly bluster. Trump tended to raise the possibility as a defensive reaction whenever he was criticized for suggesting that allies pay more for their own defense. But it’s also clear that Trump doesn’t believe in rules or norms. The problem with his approach to proliferation in Iran and North Korea is that it is not, fundamentally, about proliferation at all.

The sanctions regimes imposed on Iran and North Korea required the cooperation of many countries, including China and Russia. Those sanctions were only viable insofar as the U.S.concerns about proliferation were seen as sincere. Trump has made it clear that Iran’s adherence to the JCPOA doesn't win it any points with him—following the rules doesn’t matter. Trump has signaled that Washington’s concern about Iran’s nuclear program is really just an excuse that justifies a thinly veiled preference for regime change. And what could make that clearer than the praise that Trump has heaped on Kim? The most dangerous aspect of Trump’s treatment of Iran and North Korea is not so much that it breaks with U.S.diplomatic tradition—although it does—asthat it may come to be seen as kind of continuity. Trump’s approach feeds the narrative that U.S. talking points about the spread of nuclear weapons are little more than convenient fictions that exist to enable other foreign policy priorities.

What we do not know is this: At what point will the decline of U.S. credibility pose a mortal threat to the legitimacy of the nonproliferation regime? Legitimacy is hard to measure, whether it is the legitimacy of an international regime or a autocracy. If it is fading away, we may not know until it is too late. Plenty of authoritarian regimes hollow out over time but lumber on as political zombies, dead on the inside but still moving. When they collapse, no one is more surprised than the regime’s own functionaries.