At the height of the Cold War, the Soviet Union had some 45,000 nuclear warheads. At the moment, Iran has none. But when Barack Obama said the obvious -- that Iran does not pose the sort of threat the Soviet Union did -- John McCain reacted as though his rival had offered to trade Fort Knox for a sack of magic beans.

"Such a statement betrays the depth of Sen. Obama's inexperience and reckless judgment," exclaimed McCain. "These are very serious deficiencies for an American president to possess."

But if Iran is the Soviet Union, I'm Shaquille O'Neal. There is nothing reckless in soberly distinguishing large threats from small ones, and there is something foolhardy in grossly exaggerating the strength of your enemies.

As military powers go, Iran is a pipsqueak. It has no nuclear weapons. It has a pitiful air force. Its navy is really just a coast guard. It spends less on defense than Singapore or Sweden. Our military budget is 145 times bigger than Iran's.

By contrast, the Soviets had far more nuclear weapons than we did, a blue-water navy, formidable air power and ground forces that dwarfed ours. In a conventional war, it was anything but certain that we could prevail, and in a nuclear exchange, it was clear they could destroy us.

Iran is a very modest adversary. Of course, even a Chihuahua can bite. The U.S. government claims Iran has provided arms and training to Iraqi insurgents -- never mind that it is allied with the government of Prime Minister Nouri al-Maliki.

But it's worthwhile to remember that even bad regimes sometimes have understandable motivations. The United States helped overthrow a democratically elected Iranian government in 1953 and provided aid to Saddam Hussein during the Iran-Iraq war of the 1980s. If Iran sees an interest in bleeding the U.S. military, that is likely a defensive response to the presence of an avowed enemy on its border rather than a sign of aggressive intent.

Its actions in Iraq, however, are supposedly the least of the menace. McCain and many others are convinced that Iran will soon get nuclear weapons and proceed to use them.

The first claim overlooks the Bush administration's own National Intelligence Estimate, issued last year, which concluded that Iran halted its nuclear weapons program in 2003. The NIE also said, "Tehran's decisions are guided by a cost-benefit approach rather than a rush to a weapon irrespective of the political, economic and military costs."

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.