Iran's decision to remove the U.N. seals on its nuclear research facilities has made obvious the failure of European attempts to cajole the mullahs into giving up their atomic dreams. The only thing the Europeans did was buy time for the Iranians to better camouflage and defend their research and production sites.

Experts estimate Iran will need only three more years to build its first nuclear bomb, and it will pass the point of no return much sooner. Within six to 12 months, Tehran might finish the enrichment facilities that will make the Persian bomb a foregone conclusion. It already has Shahab-3 missiles that place Israel and U.S. forces in Iraq and Afghanistan within easy range. In the works are a Shahab-4, which would be able to hit Western Europe, and a Shahab-5, which would reach North America.

An Iranian nuke is not a reassuring prospect, given that country's well-earned designation by the State Department as the world's leading state sponsor of terrorism. The mullahs serve as godfathers to, among other organizations, Hamas, Hezbollah and Islamic Jihad. They are suspected of providing weapons and training to terrorists inside Iraq. And they have sheltered senior members of al-Qaida while claiming to have detained them.

Making the situation more alarming was last year's "election" (by an undemocratic process) of Mahmoud Ahmadinejad, a former member of the Revolutionary Guards (Iran's SS), as president. He has made headlines with claims that the Holocaust never occurred and that Israel is a "tumor" that should be "wiped off the map." Western analysts comfort themselves that he doesn't really mean it; surely he's only posturing for a domestic audience. Isn't that what people said about Hitler? When dictators make bellicose statements, prudence dictates taking them seriously.

Especially because the dictator in question gives every sign of being a genuine religious zealot who believes in the imminent arrival of the Mahdi ("divinely guided one"), a messiah who will herald the end of days. Ahmadinejad has said that he was bathed in a divine aura when he spoke to the U.N. General Assembly last year calling for the "promised one, that perfect and pure human being," to return to Earth.

In sum, a terrorist-sponsoring state led by an apocalyptic lunatic will soon have the ability to incinerate Tel Aviv or New York.

The International Atomic Energy Agency is concerned enough to convene an emergency meeting on Feb. 2 to discuss a referral to the U.N. Security Council. This is not a prospect to make the mullahs quake. They know perfectly well that no serious sanctions are likely. Their business partners in Russia and China will see to that. Nor do the Europeans have any interest in embargoing Iran's main export — petroleum — when oil is more than $60 a barrel. The most that might happen is that some Iranian officials might have their foreign accounts frozen and their foreign travel curtailed. That seems a small price to pay for nuclear glory.

What might stop Iran at this late date? Some conservatives have pinned their hopes on another Iranian revolution. The CIA and other agencies should do everything possible to encourage such an uprising. But the chances of regime change in the near term are not high. Even less likely is a U.S. invasion; the U.S. military is overstretched as it is.

That leaves only one serious option — air strikes by Israel or the U.S., possibly accompanied by commando raids. It is doubtful that bombs could eradicate Iran's nuclear program, but they could set it back for years, possibly long enough for the regime to implode.

There are two major downsides cited by opponents of military action. First, they say, an attack might lead Iranians to rally around the current regime. Possibly. But it might instead expose the mullahs' weakness and thus undermine their authority. The second objection is more serious. Even if air strikes are carried out by Israel, the mullahs would almost certainly order terrorist retaliation against the United States and step up efforts to sabotage our activities in next-door Afghanistan and Iraq. These are real worries. But do they outweigh the consequences of letting Iran go nuclear?

Sooner rather than later, President Bush must face a hard choice: Either order air strikes (or acquiesce to Israeli strikes) or accept a nuclear-armed Iran. A lot of bluster won't make this dilemma disappear.