Still, a policy of bombing now could avoid the uncertainties and dangers of a deterrence policy, at least for a few years. We could delay having to face up to the difficulty of shaping the responses of Iran's neighbors to Iran's acquisition of a bomb, and we could keep the option of forcible regime change on the table. Bombing would not, however, prevent the prospect of Iranian escalation against Israel; rather, it would increase that prospect in the short run. But the ultimate question that must be asked about bombing is whether one believes that the mullahs are fundamentally undeterrable. If they are, all of the other assumptions about various policy options become irrelevant. Given available evidence and the track record of the Iranian leadership since the Islamic revolution, however, it is unwise to assume that the clerical government in Tehran is undeterrable. Iran has shown that it will take risks where it perceives benefits but back down where the potential costs become too high. Moreover, delaying Iran's nuclear program is the only conceivable benefit that could likely be derived from a policy of preventive war. Juxtaposed against that benefit are an array of negative consequences, varying from merely undesirable to deeply dangerous. The assessment of the merits and demerits of deterrence necessarily presents a mirror image of the above analysis. The dangers of war would be avoided, but a host of other challenges and new concerns would emerge. Still, it is worth examining the benefits of not bombing. Embracing a posture of deterrence would, in the first instance, prevent the inevitable loss of American life that would result from a war. Moreover, billions, if not hundreds of billions, of dollars would be left in the productive economy rather than being allocated to attempting to set back Iran's nuclear program. The mullahs in Iran would remain unpopular, unable to use the American bogeyman to consolidate support internally. We could also avoid the range of Iranian countermeasures: further chaos in Iraq, attacks against U.S. troops in that country or against Israel, and the prospect of sky-high oil prices and volatility in the Strait of Hormuz. The problems of chaos in post-regime-change Iran, should a conflict escalate to that level, could also be avoided. In the end, it is difficult to avoid the conclusion that, absent some very shaky assumptions about the Iranian leadership's rationality, deterrence is a preferable policy to preventive war. The preventive war option unleashes so many forces that are beyond the control of the American government that it should be looked on as a supremely undesirable policy. And given the historical record of the revolutionary Iranian leadership and the history of deterrence in the international system, deterrence appears to be highly preferable.