Talk of a U.S. attack on Iran is like a late-summer thunderstorm that rumbles ominously in the distance without ever drifting further away. Few American observers advocate an immediate attack, but a growing number hint that the question is when, not if, a strike takes place. The distance from saber-rattling to war is narrowing.
As is often the case in the prelude to war, the discussion has so far been informed more by passion than by analysis, stoked by popular distrust of the Iranian regime. As the United States found when contemplating the invasion of Iraq in 2002, such an over-heated environment makes it difficult to coolly assess alternatives. But to avoid disaster, that is exactly what we must do. The burden of proof lies with those who contend that an attack is necessary and that the strategic benefits for U.S. national security outweigh the costs. So far advocates of military action have not made their case. If they are to do so, they must first answer three central questions.
What do we mean when we say a nuclear-armed Iran is unacceptable? Both President Barack Obama and Republican presidential nominee Mitt Romney have stated that a nuclear-armed Iran is "unacceptable," a word echoed by most proponents of an attack. What they have not explained is whether they are using the word in its literal sense, meaning that the United States must shoulder any cost to prevent a nuclear-armed Iran, or whether they mean it figuratively, in which case the United States will only bear some undefined but delimited cost and risk. If a nuclear-armed Iran is literally unacceptable, then invasion and occupation -- which would require a significant increase in defense spending and probably a military draft -- as well as pre-emptive nuclear strikes must be on the table. Is that really what attack proponents mean?