In March, then-candidate Donald Trump shocked nuclear policy experts by suggesting at a town hall meeting that the United States might be able to reduce the defense budget by encouraging its allies, especially Japan and South Korea, to build nuclear weapons. When pressed to clarify his comments by the moderator, CNN's Anderson Cooper, Trump replied, "Wouldn't you rather in a certain sense have Japan have nuclear weapons when North Korea has nuclear weapons?" Earlier that same week, Trump told Bloomberg's Mark Halperin that it was important to remain "unpredictable" when dealing with nuclear weapons.

Since the end of the World War II — the only time that atomic weapons have been used in war — the policy of the United States has been to discourage nuclear proliferation, whether through defense treaties, economic sanctions or controlling international sales of uranium. Similarly, the concept of nuclear deterrence depends on rational, predictable decisions about the use of nuclear weapons. Trump's statements naturally caused a flurry of panic over an untested leader with little familiarity with the basic principles of nuclear security having control of atomic weapons.

It may be time to resurrect a Cold War strategy for limiting nuclear risk: back-channel communications among private scientists.

In 1955, a year after the U.S. test of a hydrogen bomb in the Bikini Atoll blanketed the globe with a thin layer of radioactive fallout, a group of scientists issued a manifesto against the development, testing and use of nuclear weapons. This inspired what became known as the Pugwash Conference. At the height of Pugwash's influence in the late 1950s and early 1960s, scientists from the United States, the United Kingdom, the Soviet Union and a handful of other countries gathered regularly to discuss the nature of the nuclear threat and ways to reduce it.

Commentators have held up Pugwash as a model of nonpartisan scientific activism, a shining example of what scientists could accomplish without the constraints of formal politics. In 1995, the Pugwash Conferences and Joseph Rotblat, one of the founders, received the Nobel Peace Prize. More recently, the Obama administration hailed the personal relationship between Secretary of Energy Ernest Moniz and Ali Akbar Salehi, the head of Iran's Atomic Energy Organization, as a critical ingredient in the nuclear agreement with Iran. The two men had overlapped at the Massachusetts Institute of Technology in the 1970s. While they obviously represented their respective countries at the negotiating table, their shared technical assumptions provided a platform on which to build political consensus.

Both during and after the Cold War, the U.S. government supported initiatives that brought international scientists together outside formal political channels. Beyond the nuclear realm, scientists have informally assisted U.S. officials in negotiating treaties on issues as diverse as climate change and exploration rights in Antarctica.

Scientists are not elected officials, and nothing in their scientific training is designed to prepare them for the subtleties of international political negotiations. The premise of science diplomacy risks putting power in the hands of technical experts whose personal interests may or may not match those of their national governments. And yet: There is no evidence to suggest that the elected head of government — Donald J. Trump — possesses the finesse needed to negotiate a nuclear crisis, either.

For the leaders of Pugwash, the point of an international scientists' movement wasn't so much to displace official negotiations between governments as to keep a line of communication open in the event of a crisis.

During the Cuban missile crisis of 1962, for example, the American members of the Pugwash Committee sent their Soviet counterparts a telegram urging restraint and promising to use whatever limited influence they had over U.S. government officials to defuse the situation. The scientists hoped that a mere reminder of their presence might jolt political leaders into recognizing the effects of a nuclear strike.

Whether or not the president-elect and his advisers realize it, Trump is going to need scientific expertise. In a normal administration, it would be a given that Trump and advisers would confer with security experts who could provide a reality check on technical questions, from the stages of nuclear proliferation to the effects of modernized nuclear weapons on theories of deterrence. But the Trump campaign has defied expectations in a number of ways, and a Trump presidency is in many ways an open question.

Should Trump decide to go forgo technical advice, Americans (and the world) should take comfort in the fact that scientists, security specialists and nuclear weapons experts from many countries will continue to talk to one another. Pugwash's scientists, too, continue to meet, forging personal links and technical knowledge that can transcend international borders. Back-channel communications among international scientists will always offer hope for preventing a nuclear catastrophe, regardless of who sits in the Oval Office.

Audra J. Wolfe is the author of "Competing with the Soviets: Science, Technology, and the State in Cold War America."

