Sixty years ago, in the aftermath of the Cuban Missile Crisis, President John F. Kennedy gave probably the greatest speech on nuclear arms ever given by an American President. Speaking only months after the crisis, Kennedy could have lashed out at the Soviet Union’s reckless behavior in putting missiles in Cuba. Or he could have taken a triumphal tone, highlighting his success in forcing the Soviets to pull the missiles out (with the public then in the dark on his secret promise to pull similar U.S. missiles out of Turkey).

Instead, in a June 10 commencement address at American University, Kennedy made the case that the horrors of a potential nuclear holocaust made it urgent to find a path to peace and that doing so required both sides of the Cold War to change. He announced that the United States would unilaterally stop testing its nuclear weapons until a treaty banning such tests could be reached. “Some say that it is useless to speak of peace,” Kennedy noted, “until the leaders of the Soviet Union adopt a more enlightened attitude. I hope they do. I believe we can help them do it.”

World response was immediate. The NATO allies hailed the speech. The Manchester Guardian ranked it “among the great state papers of American history.” The Soviets turned off their giant radio jammers so that Soviet citizens could hear the speech on Voice of America, and they printed the full text in both Pravda and Izvestia. (The Soviets had some warning: Kennedy’s team had consulted with them informally before he gave his speech.)

Although the Soviets made no formal announcement of a testing halt, they, too, paused nuclear testing. Less than ten days after Kennedy’s speech, the United States and the Soviet Union agreed to the creation of a “hotline” between the two governments. In a month and a half, the Limited Test Ban Treaty had been completed, putting an end to the constant explosions that were spewing radiation across the world, contaminating even mothers’ milk. Kennedy called the treaty “a victory for mankind,” and said that even if the journey to peace was a thousand miles, “let history record that we, in this land, at this time, took the first step.” Soviet leader Nikita Khrushchev hailed the treaty in similar terms.

In the months that followed, the two sides each announced unilateral cutbacks in the production of fissile material for nuclear weapons; reductions in their military spending; and modest pullbacks of troops from the front lines in Central Europe. None of these initiatives were negotiated in detail ahead of time, or verified, though there were informal consultations on each one before they were announced. Khrushchev called it “a policy of reciprocal example in the matter of reducing the armaments race.”

At the UN, the sides also managed to reach an agreement on the Outer Space Treaty, banning nuclear weapons in orbit. The atmosphere of heated Cold War confrontation changed markedly, paving the way for the start of negotiations of the Nuclear Nonproliferation Treaty and then strategic arms talks.

Kennedy’s initiative—sometimes called “the Kennedy Experiment”—drew on the ideas of psychologist Charles E. Osgood, who had published a paper on a strategy he called “Graduated Reciprocation in Tension-Reduction,” or GRIT. The concept was that with two sides in a high state of tension, one side could unilaterally take a tension-reducing step—large enough to be noticed, but small enough not to endanger its security—and challenge the other side to take a step of its own. Osgood argued that the challenge should not be a specific demand, because, in such a state of high tension, the other side would likely see a specific demand as asking too much. Osgood proposed that the first step be accompanied by an unambiguous statement of a new, peaceful policy—exactly what Kennedy did in his American University address.

Osgood went further and argued that even if the other side did not reciprocate—perhaps not fully accepting that its adversary was genuinely trying to reduce the temperature—the side trying to reduce tension should continue with additional small steps, to make the changed approach impossible to deny. It is that idea of continuing even without any positive response that most justifies the GRIT acronym. If the other side did reciprocate, then the initiating side could take a somewhat larger step and see if that was also reciprocated. Osgood hoped to “run the arms race in reverse.”

Osgood suggested that if the opponent makes a warlike move, there should be a “measured response”: enough to show the opponent that the new strategy did not indicate weakness, but not so much as to close the door to further progress.

Decades after Kennedy’s initiative, this approach worked again. In 1991, as the Soviet Union hurtled toward collapse, President George H.W. Bush announced a dramatic set of unilateral initiatives, pulling back U.S. tactical nuclear weapons from around the world (except for a small force that remained in Europe) and destroying most of them; eliminating nuclear weapons from surface ships; and taking strategic bombers off alert. The Soviet Union, and then Russia, reciprocated with similarly sweeping (though not identical) reductions. These “Presidential Nuclear Initiatives” resulted in the fastest nuclear arms reductions that have ever taken place.

Today, tensions between Washington and Moscow are higher than they have been since Kennedy spoke, after Russia’s brutal invasion of Ukraine and repeated nuclear threats. Hostility between the United States and China is growing—and North Korea’s dictator keeps up a relentless pace of missile testing and reckless nuclear rhetoric. These tensions between nuclear-armed states matter: the more hostile two states are, the more likely it is that a crisis will occur, that the crisis will escalate to conflict, and that conflict will escalate to the use of nuclear weapons. Hence, in each of these cases, it is time for new action to bring down the temperature.

President Joe Biden has taken a few small initial steps. The Biden team announced that the United States would unilaterally pledge not to conduct direct-ascent antisatellite (ASAT) weapon tests that would create showers of space debris, endangering other satellites. And they put forward a set of political commitments on “responsible” military use of artificial intelligence—including a commitment that the decision to use nuclear weapons would always be made by a human, not a machine. Scores of other countries have signed on to the ASAT initiative—though not, so far, Russia or China.

Unfortunately, Biden faces obstacles to doing more that President Kennedy did not. In particular, Kennedy spoke when the Cuban Missile Crisis was over: the Soviets had withdrawn their missiles. Today, Russia’s war on Ukraine continues, with new violations of the laws of war almost every day.

Nevertheless, the need for reducing tensions is urgent, and there is more Biden could do. He could announce that a portion of U.S. nuclear missiles would be taken off alert: surely not all of them need to be ready for immediate launch. He could commit that the United States would never use nuclear weapons first unless the very survival of our country or one of our treaty allies was at stake. He could commit that the United States would never deploy its missiles where they could reach Moscow or Beijing in just a few minutes. He could offer to let Chinese or Russian experts monitor U.S. weapons-maintenance experiments to confirm American compliance with the nuclear test ban. He could commit that all U.S. nuclear enrichment and plutonium reprocessing activities would be available for international inspection to confirm they were not being used to make new material for nuclear weapons.

None of those steps would endanger U.S. security. If reciprocated, each of them would improve security significantly. They might be a first step toward new arms restraints that could take the place of New START—the last remaining treaty limiting U.S. and Russian strategic nuclear force numbers—when it expires in early 2026.

The world today is very different from the world of six decades ago. But the need to manage hostility among nuclear-armed states is no less. Biden should draw on Kennedy’s example and pursue new steps to reduce nuclear dangers.

Matthew Bunn is the James R. Schlesinger Professor of the Practice of Energy, National Security, and Foreign Policy at Harvard Kennedy School and Co-Principal Investigator for the Project on Managing the Atom at the Kennedy School's Belfer Center for Science and International Affairs.

Image: Courtesy of the JFK Library.