Even if Iran were to acquire atomic bombs, there is no reason to think it would use them or turn them over to terrorists. McCain, however, insists that Iran has "a commitment to Israel's destruction," and appears to think its leaders cannot be contained because of their religious fanaticism.

But as University of Michigan Middle East scholar Juan Cole has explained, Iranian President Mahmoud Ahmadinejad never vowed to "wipe Israel off the map" -- an oft-quoted phrase that Cole says is a mistranslation of the milder words he used. In fact, he says, "Ahmadinejad has never threatened Israel with physical aggression," however much he would welcome its collapse.

Even if the Iranians would like to destroy Israel, they face a powerful disincentive: the prospect of radioactive incineration. The Tehran government has been intimidated by less. Israeli historian Gershom Gorenberg writes in the May/June issue of Foreign Policy magazine, "Iran agreed to a ceasefire in the war with Iraq once Iraqi missiles began falling on Tehran. The ayatollahs were willing to sacrifice soldiers -- but not to pay a higher price." Even fanatics have their limits.

Nor would Iran be so irrational as to give nukes to a terrorist group. That would be the worst of both worlds -- giving up control of those weapons, while inviting annihilation the moment they are put to use.

But there is no reasoning with McCain and his allies, who yearn for the simple clarity of the Cold War. If we don't have an enemy on the mammoth scale of the Soviet Union, they will take a pint-sized one, inflate it beyond recognition and pretend that military confrontation is the only way to deal with it.

That was how we got into the war in Iraq and how, under a McCain presidency, we are liable to end up in a war in Iran. If he's looking for reckless judgment, he should look in the mirror.