Bush's threats aren't very scary

Matthew Yglesias makes a good point about Iran's response to U.S. sabre rattling:

Another word on Iran. Hawkish-minded commentators seem to be observing that the Iranian regime doesn't appear especially frightened by the prospect of American air strikes. They're concluding from this what they invariably conclude from everything -- that we need to be more hawkish in our posture in order to frighten Teheran. They assume that the Iranian leadership's lack of fear is based on their estimation of our military capacities, our resolve, or something along these lines. They ought to consider another possibility -- Bush's threats aren't very scary.

American experts disagree on the extent to which air strikes can destroy or set back the Iranian nuclear program. I have no idea what anyone is basing their estimates of this question on. There's universal agreement, however, that we can't destroy everything if for no other reason than we can't be sure where everything may be. Thus, the Bush administration's démarche amounts to the following -- either abandon your nuclear program or we'll partially destroy your nuclear program. This is not a very difficult choice to make. In addition, the regime in Teheran probably believes that unilateral American strikes on Iran will create the opportunity for an enormous propaganda win for Teheran, both domestically and internationally. All else being equal, they'd prefer not to have their nuclear program even partially destroyed. But since not having the program destroyed isn't on the table, and the administration isn't putting anything else of note on the table in exchange for voluntary disarmament, it's a no-brainer to just let the bombs fall where they may.