Iranian Trip Wire

The West's standoff with Iran reached an ominous point recently when Tehran hinted that it might expel inspectors from the International Atomic Energy Agency should the U.N. Security Council approve any new sanctions against it. The closing of this final window into Iran's nuclear program would be a grave blow to global security. The West may have little choice but to respond with military action.

Iran is currently producing a large batch of lightly enriched uranium at its Natanz facility. According to experts, Iran could be ready to begin turning that batch into highly enriched, weapons-grade uranium in a matter of months. But Iran can't take that next step as long as inspectors have access to Natanz. So unless it is willing to build parallel nuclear facilities secretly — with the cost and risk that entails — Iran will have to shut the inspectors out of Natanz before it can proceed with its weapons development.

The strategy of using Security Council sanctions to force Iran to abandon this pursuit has not merely failed, as IAEA chief Mohamed ElBaradei recently argued. It has utterly backfired, and for reasons that the British, French and Germans who devised it — and the Bush administration, which approved it — should have foreseen.

First, once the IAEA referred Iran's case to the Security Council in February 2006, the use of force was implicitly taken off the table for as long as the Council could keep producing tougher resolutions. Because Iran could drag this process out for at least a year, it knew that it would have enough time to achieve large-scale uranium enrichment without risking military action. In effect, the European negotiators enticed Iran to sprint toward this capability, and thus have achieved precisely the opposite of what they had hoped.

Second, the incremental sanctions gave Iran an excuse for incremental withdrawal from the IAEA. After last year's referral to the Security Council, Iran stopped allowing “anytime-anywhere” inspections. In response to the last resolution, Iran announced that it would no longer notify the IAEA of plans to build new nuclear facilities — a partial abrogation of the nonproliferation treaty that went largely unnoticed because Iran happened to be holding 13 British sailors hostage at the time. Inspectors now have access only to Iran's declared nuclear facilities. That, says one Western diplomat close to the IAEA, is the bare minimum the world needs to have any visibility into its nuclear program.

Sanctions are still an integral part of containing Iran. The offer to lift them will be an enticing carrot one day when Iran has a peaceful government willing to give up its nuclear weapons program in exchange for an end to isolation, as South Africa and Libya did. But as sticks meant to halt Iran's uranium enrichment, the sanctions by themselves were destined to fail — the nuclear program is simply too important to the mullahs.

As the Iran nuclear crisis enters its decisive phase, the West must put the military option back on the table. The terrifying consequences of this messianic regime's acquiring nuclear weapons will become manifest the moment Iran withdraws from the IAEA: the possibility of nuclear terrorism, of medium-range missiles that could be nuclear-tipped, of mullahs who might feel less restrained by deterrence of any sort. Because of the intolerable uncertainties it would create, Iran's withdrawal from the IAEA would be an act of aggression against those states that Iran so routinely and breezily threatens. As Henry Kissinger once said, it is sometimes necessary to threaten the use of force in order to avoid its use.

The last best chance to keep Iran from going nuclear may be to attach a trigger for military action to Iran's refusal to cooperate with the IAEA. Even inside the Iranian regime, there are those who warn that such a refusal would be needlessly reckless. The West must strengthen their case by reserving the right to use force in defense of basic security. The Iranian regime and people may be united behind Iran's right to nuclear technology, but they are not united behind the ruling hard-liners' disregard for international law and national standing. Iranian officials have repeatedly insisted that they want to assure the world of Iran's compliance with the nonproliferation treaty. That is the point the West can challenge the mullahs on.

Iran's strategy of incremental withdrawal from the IAEA is vastly more clever than the West's strategy of incremental sanctions. Rather than precipitate a crisis, Iran carefully tests the West's resolve with small steps: the exclusion of a few inspectors here, the elimination of certain disclosures there. What the West has made very clear is that none of those steps carry any risk at all. Here, the West's policy must do an about-face.

What's more, even if Iran doesn't withdraw from the IAEA, its current level of cooperation will become less useful the closer it gets to industrial-scale enrichment capability (i.e., the ability to produce nuclear weapons on a large scale). Greater transparency is needed. So, any agreement that accepts Iran's continued enrichment of uranium on a small scale, as Mr. ElBaradei recently proposed, should accordingly insist on Iran's return to anytime-anywhere inspections. In fact, that might be worth a significant concession on sanctions.

If Iran instead moves the other direction and eliminates what little transparency remains in its nuclear program, it would be foolish for the West not to assert the right of self-defense — and reckless not to consider the use of force. To be sure, military action is a frightening option. Iran might react by escalating any conflict to a full-blown war. But by gleefully casting aside the U.N. Charter, and by refusing to address the legitimate security concerns of other states, Iran is the one propelling the current crisis toward military confrontation. It should be held accountable for the consequences.

Iran's cooperation with the IAEA has become vital to the security of the West. For the sake of peace, let's be clear that it is also vital to the security of Iran.

Mr. Loyola is a fellow at the Foundation for Defense of Democracies.