Recently President Ahmadinejad, Iran’s outspoken leader, said, “Life is shaped by art and the highest form of art is martyrdom.” This is the statement of a man possessed. If taken along with his Holocaust denial claims and threats to wipe Israel off the map, this is a person who at the very least cannot be trusted. It is therefore critical that he is denied the nuclear weapons he craves. His uranium enrichment program is well on the way to conclusion and in months, perhaps a year, Iran will be in possession of the knowledge necessary to produce a nuclear weapon.

The central question now is whether he can be stopped and whether the West has the will to do it.

President Bush has made it abundantly clear that he will not tolerate a nuclear bomb in Iran. Yet even a determined president has limitations. Can the Air Force destroy the Iran facilities? Will there be retaliation? How will the Muslim world react to such an action? And will there be collateral damage that unites Iran and makes it an even more formidable threat than is the case at the moment?

These are serious questions, and yet the situation is not hopeless. The West, should it find the will to act, has several factors working in its favor. For example, the “cascading effect” needed to produce high grade uranium is probably in one major site even though ancillary activities may be dispersed. Therefore sorties carefully directed using bunker-buster bombs could probably do the job against a reinforced underground facility.

Meantime, while the Iranians have missiles that can reach Tel Aviv, they probably don’t have nuclear weapons yet. Therefore, they might deploy missiles tipped with chemical and biological weapons. While the prospect of such deployment is horrible to imagine, these weapons are unreliable. On the conventional front Iran is simply no match for Israeli forces, much less American military operations.

Although it is impossible to determine how the Muslim world would respond to such an attack, it is noteworthy that the much vaunted Arab street did not rise in unity against the liberation of Iraq and one might reasonably expect that will be the case in an attack on Iran.

Collateral damage is always a possibility even in the age of smart bombs. But the targets are limited and the precision bombs are increasingly more refined and accurate. Therefore, it is probable that casualties would be limited. In fact, rather than unify Iran, such destruction of the nuclear facility might be the occasion for dissident groups to rise up against the ruling mullahs.

Recently there has been a lot of chatter about funding for public diplomacy that might encourage regime change, but it is important not to view this by itself as an alternative to a military solution. There have been many opportunities for rebellion against the repressive regime, but thus far the secret police have been able to control the outbursts. And it takes time to cultivate a pro-democracy movement that can topple a regime on its own. While regime change would be a desirable outcome, and a measure worth trying, we are running out of time. The clock is ticking on the prospective acquisition of a nuclear weapon. Likewise, the clock is ticking on the European initiative to halt the Iranian program. Thus far, the negotiations have merely served as a cover for the continued development of the program, even if this diplomatic exercise is a necessary prerequisite for consensus on military action.

Security Council resolutions that lead to an embargo might be effective if the embargo on oil holds and if this isn’t interpreted by Iranian leaders as an act of war. Of course, getting unanimity in the Security Council is a long shot with the Russians poised to veto an embargo and China, sitting on the sidelines, bemused by the prospect of the U.S. groveling for support.

Any way you cut it, military force seems like the most likely stratagem for success. Will Bush do it? He cannot afford not to do it. His legacy cannot be a nuclear Iran prepared to destabilize all of the Middle East and possibly Europe. This is yet another test of American will. While the Democrats, in large part, will criticize the decision, there is little doubt the American people will support the president, especially if he runs out the string on other options and points out that force is the only realistic alternative.

Mr. London is president of the Hudson Institute.