Then he decided to tilt the whole global balance of power to the Soviet Union’s advantage by installing nuclear-tipped missiles in Cuba. Which he proceeded to do with Fidel Castro’s enthusiastic, not to say bellicose, cooperation. Or as Nikita Khrushchev put it in his always refined way, it was time to “throw a hedgehog at Uncle Sam’s pants.”

The result was the Cuban Missile Crisis of 1962, the closest the world has come to nuclear holocaust. By then John F. Kennedy had learned a thing or two; he never deigned to negotiate with Fidel Castro, and he made it clear from the outset that a nuclear attack on this country from Cuba would be met as if it had originated in Moscow, as indeed it would have.

After a long, elaborate, and nerve-wracking diplomatic dance, complete with a naval embargo of Cuba and many a crisis within the crisis, the missiles were removed. Things had worked out somehow. But it was still, as the Duke of Wellington said of Waterloo, a damned close-run thing ? much too close for comfort. And it had its origins in an ill-considered meeting without proper preparation.

And this is the meeting Sen. Obama uses to justify his open-ended, no-conditions offer to meet with some of the most fanatical anti-American leaders in the world, at least one of whom - Iran’s nutcase president - has been trying to acquire a nuclear arsenal for years. (And he’s making good progress to the regular accompaniment of irresolute UN resolutions against a nuclear-armed Iran.)

Let it be noted that, by the time John F. Kennedy went to Vienna, he’d already served six years in the House and eight in the Senate. A combat veteran and war hero, he’d spent more time in the Navy than Barack Obama, a freshman senator, has spent in the U.S. Senate. And he was still blindsided at Vienna.

By now Sen. Obama has backtracked slightly on his offer to meet the Mahmoud Ahmadinejads and Kim Jong-Ils of the world with no preconditions. Which is a welcome development. But that he should use a young president’s diplomatic blunder as an example to emulate. … Well, it does not encourage confidence in his judgment. To put it mildly, it betrays a marked insensitivity to the lessons of history. Which is troubling.