In his years piloting the presidential nuclear command aircraft during the peak of the Cold War, Barry Walrath began to notice a pattern. The specially modified Boeing 747, known to the Air Force as an E-4B Nightwatchplane, was one of the primary places from where a president could lead the nation into war, and the crew’s key task was to train for a nuclear conflict, over and over and over again.

These drills, code-named Silver Dollar, always involved a Pentagon or White House official playing the role of the president — the National Command Authority who had unchecked power to launch nuclear weapons. Once the plane was airborne, the drills unfolded the same way. The “president” would receive a mock briefing about geopolitical tensions underway, which would quickly escalate into a thermonuclear exchange. Then would come the moment of truth: The Nightwatch crew would ask for a launch order.

That’s where the system, Walrath noticed, would stop. “No one would ever press the button — even when it was clearly a drill, even when someone had been told nothing would happen,” he recalls. “It just seemed too real. You’ve suspended disbelief. It was nasty.”

The exercises led Walrath to doubt that in the heat of the moment, faced with the horror of a global thermonuclear war, the United States would ever actually launch weapons. In every training exercise, the “president” would wait at least until missiles hit the U.S. before ordering retaliation. Often, he or she would not order a strike at all, watching as the scenario unfolded and the U.S. was obliterated. “I always wondered, if the Soviets had had any idea how reluctant we were to launch a missile, they might’ve felt entirely different,” Walrath says. “It wasn’t unusual to do nothing at all in response.”

Walrath’s observation has hung over nuclear war planning for generations. There’s almost no question that, if ordered to do so, the military chain of command would execute a valid launch order quickly and decisively. But what if the president would never issue such an order? What if the nuclear deterrent, the cornerstone of security for decades, is a hollow promise, perhaps on both sides? Presidents and heads of nuclear states have always played their cards close to their chests — the entire idea of deterrence would collapse if adversaries knew they could attack with impunity. But there’s plenty of evidence from the Cold War that nuclear war was literally unthinkable, that the men in charge might never have pushed the button.

That question is worth revisiting today, as President Donald Trump and Kim Jong Un stare each other down across the Pacific, each wondering if the other would launch a nuclear strike. Even as the latest rhetorical fireworks appear to have passed, more tense moments no doubt lie ahead if North Korea continues its efforts to master a nuclear-topped intercontinental ballistic missile. But the eventual launch of such a missile is far from a sure thing. Indeed, the evidence from the Cold War perhaps offers some comfort that at the decisive moment, one or even both sides might blink and step back from the abyss.

Cold War presidents devoted extensive time to understanding the nuclear arsenal and sitting in on exercises — though by tradition, commanders in chief didn’t play the role of the president, to ensure that they never tipped their hand about how they’d respond to a real crisis.

In May 1969, Richard Nixon flew aboard that presidential “doomsday plane.” In its conference room, the battle staff led him through an exercise modeling the execution of SIOP, the Single Integrated Operational Plan, which served as the nation’s nuclear war plan. “Pretty scary. They went through the whole intelligence operational briefing and a test exercise — with interruptions to make it realistic,” White House Chief of Staff H.R. Haldeman wrote in his diary that night. “Took P a while to get into the thing (his mind was on the peace plan) but he finally did — and was quite interested. Asked a lot of questions re: our nuclear capability — and kill results. Obviously worries about the lightly tossed-about millions of deaths.” Afterward, national security adviser Henry Kissinger knew that Nixon would never push the button. The president had been so chastened by the exercise that he would never launch such an insane all-out war. As Kissinger cautioned behind closed doors after Nixon heard about SIOP, “If that’s all there is, he won’t do it.”

If true, Nixon’s approach might not have been out of line with that of his predecessors. Harry Truman, the only man in history to order a nuclear weapon’s use, cut short one Oval Office debate about military vs. civilian authority over the bomb. “You have got to understand that this isn’t a military weapon,” Truman said. “… It is used to wipe out women and children and unarmed people, and not for military uses. So we have got to treat this differently from rifles and cannon and ordinary things like that.”

During a January 1956 meeting on war planning at the White House, Dwight Eisenhower aggressively confronted his advisers. None of them, he complained, “had withdrawn into a quiet room and contemplated … the real nature of a future thermonuclear war.” No one, he said, could imagine “the chaos and destruction which such a war would entail.” There would be no winner. “The destruction,” the president told the group, “might be such that we might have ultimately to go back to bows and arrows.”

In another meeting, Eisenhower argued that nuclear war was not a real option, and thus widespread, serious planning for it was a waste of time and money. It wasn’t merely a matter of building better weapons or deeper shelters if a nuclear conflict came: “There just aren’t enough bulldozers to scrape the bodies off the street.”

For his part, Lyndon Johnson lived in fear of the button. “When Richard Nixon took the oath,” Johnson recounted, “the greatest burden lifted from me that I have ever carried in my life.” He explained, “Never a day went by that I wasn’t frightened or scared that I might be the man that started World War III.”

Contemplating the reality of World War III in 1983 led Ronald Reagan to dramatically shift his approach to the Cold War. That fall, he finally sat through a SIOP exercise — he’d long delayed it, saying there wasn’t much point in practicing nuclear war — and also watched the ABC doomsday movie “The Day After.” The much-hyped film starred Jason Robards and followed the residents of Lawrence, Kan., through the awful process of piecing society back together after a nuclear attack obliterates America; graphic and violent in ways that were new for TV depictions of nuclear war, the movie’s four-minute attack sequence and the death, maiming and destruction that followed were meant to leave viewers unsettled. And the film deeply affected Reagan. “It is powerfully done,” he wrote in his diary. “It’s very effective and left me greatly depressed. … My own reaction was one of our having to do all we can to have a deterrent & see there is never a nuclear war.” Reagan biographer Edmund Morris later reported that it was the “first and only admission I have been able to find in his papers” that the president was ever “depressed.” Reckoning with war as he did that fall led Reagan to dramatically alter course, toning down his “evil empire” rhetoric about the Soviet Union.

These realizations that nuclear war was not a real option didn’t occur only in the United States. Former French President François Mitterrand once said he doubted that any French leader would have launched that nation’s nuclear weapons. The only British prime minister who has ever spoken publicly about the question, James Callaghan, who served from 1976 to 1979, recalled “terrible doubts” about whether he’d ever have ordered a strike: “If I had lived after having pressed that button, I could never, ever have forgiven myself.”

The clearest misgivings, though, were expressed by the man who “blinked” in the showdown with John F. Kennedy during the Cuban missile crisis. When he took over the Soviet Union at the height of the Cold War, Nikita Khrushchev received the standard briefing about his nation’s nuclear authority. It left him shaken. “I couldn’t sleep for several days,” he recounted later. “Then I became convinced that we could never possibly use these weapons, and when I realized that I was able to sleep again.”

Khrushchev’s words offer some comfort that Kim Jong Un might understand the dirty secret of the Cold War: The entire point of building nuclear weapons is to ensure that you never have to use them.


Garrett M. Graff is the author of “Raven Rock: The Story of the U.S. Government’s Secret Plan to Save Itself — While the Rest of Us Die.” He wrote this article for the Washington Post.