Fred Kaplan is Slate's "War Stories" columnist and author of the forthcoming book, The Insurgents: David Petraeus and the Plot to Change the American Way of War.

The Cuban missile crisis broke out 50 years ago this month, and its lessons on weakness, strength, and compromise have been recited ever since by politicians, pundits, and historians. The problem—which has plagued U.S. foreign policy time and again—is that these lessons are myths, based on sheer lies about how the crisis began and how it ended.

One of these myths has been thoroughly exploded (though many eminences seem not to know it). This is the notion that President John F. Kennedy got Soviet Premier Nikita Khrushchev to back down and remove his nuclear missiles from Cuba entirely through the threat of force. In fact, as revealed by JFK’s secret tape recordings of his meetings with senior advisers (evidence that’s been available at the Kennedy Library for 25 years now), the two leaders brokered a deal: Khrushchev would take his missiles out of Cuba; Kennedy would take his very similar missiles out of Turkey.

But the other myth, no less pernicious in its impact (and no less false), still endures. This is the legend that Kennedy cowered before Khrushchev at a summit in Vienna in the spring of 1961 and that, as a result, the crafty Communist aggressively deployed missiles in Cuba thinking the young president was too weak to respond.

In fact, however, the evidence—much of it declassified a decade ago from the Kremlin archives, and recounted in Khrushchev’s Cold War, a superb book by Aleksandr Fursenko and Timothy Naftali—reveals that it was Khrushchev who shipped the missiles out of weakness and insecurity...