Unthinkable by Kenneth M. Pollack Page A

far more than they have contributed to meaningful shifts in the balance of power—or even threatened the leadership of key states. Although they keep trying and someday might succeed, Iran has never overthrown the government of an American ally. Likewise, it has exacerbated a lot of regional conflicts but never caused one. In short, my reading of the history is that both nuclear deterrence and containment of Iran are powerful concepts that have proven themselves reliable over time.
    Nevertheless, I recognize the dangers of both, and am concerned about how Iran’s acquisition of nuclear weapons could change the dynamics that produced both of those historical patterns of success: nuclear deterrence and containment of Iran. The problems that loom largest to me are the potential for nuclear crises, especially in the early years after Iran acquires a nuclear weapon but has not yet learned the rules of the nuclear road; the potential for proliferation, particularly by Saudi Arabia and perhaps the UAE; the potential for the oil market to go haywire; andthe potential for Khamene’i’s successor to prove more dangerous than he is. In general, I am concerned about each of these problems, but I suspect that each is not catastrophic to begin with and could be significantly mitigated by American action.
    Crisis management is my greatest concern about containing a nuclear Iran. I am far more concerned about the potential for crises to escalate than I am about the impact of more aggressive Iranian unconventional warfare. I expect that a nuclear Iran would become more aggressive in its support for terrorism, insurgents, and other subversive groups, and I believe that will further destabilize the Middle East. But given the accomplishments of Iranian unconventional warfare to date, I do not see an expansion of that effort as a compelling argument in favor of going to war with Iran instead. That is especially so since it seems highly likely that an American air campaign would cause the Iranians to do exactly the same thing, perhaps with even greater zeal and less restraint, since they will have just been attacked. In contrast, if the United States were relying on containment, Iranian subversive efforts would take place under a rubric of red lines and a desire to poke at us without provoking us. In fact, unless Iran finds a way to overthrow a foreign government in a way it never has in the past, the worst that is likely to happen from this would be that Iran’s efforts would provoke a nuclear crisis. That would certainly be dangerous, but what would make it dangerous was the fact that it was a nuclear crisis, not the Iranian subversive activities. So that just brings me back to my concern about nuclear crises.
    Crises, especially nuclear crises, suffer from a variety of inherent problems related to time, uncertainty, communications, all of which are going to be worse with the Iranians simply because of the nature of their system and their perceptions of the United States. However, as I have also described in the preceding pages, there are important mitigating factors. The first is that the logic of nuclear deterrence is incredibly powerful, and I have seen nothing in Iran’s behavior under Khamene’i, or even Khomeini for that matter, that makes me feel that they will not understand it as well. I feel quite comfortable about that judgment. I wish that I couldbe certain, but that is never possible and the small residual doubt cannot be allowed to be determinative. We could not be certain that nuclear deterrence would work with the Soviet Union, China, Pakistan, or North Korea either, yet it has worked in every case so far.
    The second important mitigating factor is that America’s possession of escalation dominance over Iran is an extremely powerful force to ensure that nuclear crises with Iran do not get out of hand, and that they end to our advantage. Once we are involved in a crisis, there is no level of warfare