By now, it’s pretty obvious that President Trump sees foreign policy as an extension of the business world. In both, his strategy has been hard-nosed brinkmanship, trying to cow businessmen and world leaders like Kim Jong-un of North Korea with his refusal to compromise, even if getting his way risks significant damage to his interests and those of his friends.

More than one administration official has described the president’s approach as the “madman theory,” the idea that one way to make a threat effective is to persuade your opponent that you’re unstable enough to follow through. Madman theory is nothing new, and there’s a reason Mr. Trump’s recent predecessors have avoided it: It doesn’t work.

Nuclear strategists have been talking about madman theory at least since Herman Kahn declared, in his 1962 book “Thinking About the Unthinkable,” that it could be effective to “look a little crazy” in inducing an adversary to stand down. This was not a recommendation to American leaders, but rather an admonition about the sorts of adversaries they might have to confront.

Behavior like that of the Soviet leader Nikita Khrushchev during the Cuban missile crisis was probably what Kahn had in mind. Khrushchev had a reputation for irrational behavior — consider his shoe-brandishing episode at the United Nations in 1960 — and seemed to confirm it by deploying nuclear ballistic missiles in Cuba, 90 miles from the American mainland.