What Happens If Iran Gets "The Bomb"?

What will happen if Iran gets "the bomb"? In contemplating this possibility, some analysts throw up their hands in horror, others are relatively calm about the results, and still others deny the possibility of such an outcome. Nevertheless, any realistic U.S. policy must consider such a scenario.

One frequently expressed concern is that Iran would consider its nuclear weapons capability to be held in trust for the Islamic world or would give custody of a weapon to someone else, perhaps even a terrorist group. Such an outcome is theoretically possible, but not very probable. With one notable and quickly regretted exception-Soviet transfer of some U-235 to China in the 1950s-no country with bomb-making fissionable materials has knowingly transferred them to anyone else.

More useful to consider is the role that nuclear weapons would play in shaping post-nuclear Iran's relationships with its neighbors-friends and foes. When all is said and done, such weapons would have little military utility except for deterrence. This would operate at four levels: to deter a conventional attack from a non-nuclear regional power; to deter an openly nuclear regional state-today only including Pakistan and India; to deter Israel; or to deter a major external power, notably the United States but, in theory at least, also including Russia.

The first case is obvious: no country with just conventional arms is likely to try the patience of a nuclear power. But in the other three cases, "proportional deterrence" would come into play. Originally developed by France, this doctrine holds that a relatively less-capable nuclear power such as Iran can deter a much stronger nuclear power (the United States, Russia, Pakistan, India, Israel) if it is viewed as able and willing to destroy "value targets" in the attacking nation even while it is being obliterated. This complex doctrine can be summarized as the "death throes" of a country under nuclear or even extreme conventional attack.

Such a doctrine depends on the potential attacker such as the United States or Israel calculating that the targets in its own country that would be destroyed in retaliation would be more "valuable" to it than the benefit (military or political) of annihilating Iran. Of course, proportional deterrence can only succeed if the potential retaliation is credible, hence the need for a survivable second-strike capability. The threat of retaliation must not be so precise that the original attacking nation can calculate with precision whether the game is worth the candle (uncertainty principle). There should also be a margin for the leadership of the attacked nation to over-respond (irrationality principle). All these ideas were worked out in detail during the Cold War.

By the same token, of course, Iran would also be subject to deterrence, as it is today by Israel, in particular. Indeed, recent commentary about Iranian advances in missile technology may not be related to a future nuclear arsenal. They are more likely to be an attempt to gain the ability to launch relatively accurate conventional warheads at Israel, counting on that capability to have some proportional deterrent effect on Israel if, for example, that country was inclined to launch an attack on Iranian nuclear facilities like that on the Iraqi Osirak reactor in 1981.

These calculations can be elaborated further. What they add up to is an Iran with one or more nuclear weapons that would not, per se, have a destabilizing effect on security in the region. That would be very much "scenario dependent." Nevertheless, as with all issues involving nuclear weapons, psychology and politics are critical elements. Indeed, if they were not-if the world had not witnessed Hiroshima and Nagasaki-we would likely have seen much more proliferation over the past 60 years, as many analysts long predicted, or even the further use of nuclear weapons in war.

As things now stand in the Middle East and are likely to stand for the foreseeable future, a nuclear-armed Iran would change the politics and the security of the region dramatically in terms of perceptions. The point need hardly be spelled out. Further, even if regional and outside countries could in time adjust to a nuclear-armed Iran, judged from today, it is highly unlikely that Iran would be permitted to gain such a capability. The United States, Israel, or perhaps some third-party would likely use whatever means necessary to prevent Iran from ever getting into that position.