Found on Letter from Gotham:

It is quite possible for Saddam Hussein to conclude that the United States could be severely damaged by a series of nuclear detonations in American cities. It would be absolutely rational for Saddam to conclude that he should string the world along while arming terrorist organizations whose sole purpose is to do just this. He would be thoroughly justified in believing that the US reaction would be to scurry around hysterically and mount an ineffectual military response.

He would be absolutely wrong to believe this. We would wipe him out in short order. But it wouldn’t be irrational for him to come to the wrong conclusions, and--we can't afford to test this thesis.

Odd definition of "rational" there. On what basis would he build this belief? The concept of rationality assumes that actors don't pull actions and beliefs out of thin air; they actually look at what's happened, interpret it, and react according to that interpretation. Considering that, what possible reason would Saddam have to believe that the "US reaction would be to scurry around hysterically and mount an ineffectual military response"? Other than its convenience in supporting Diane's theory? The U.S. is itching for a reason to get him, most of the world's objections are based on the idea that the U.S. needs a reason, Saddam using any sort of WMD would constitute just such a reason, and the world community has shown that it has no qualms about acting against Saddam when it is supported by international saction (witness the Gulf War.)

I commented on the sort of risk/reward analysis that Saddam would likely do earlier, and echoed Hesiod's conclusion that using terrorists to nuke the U.S. would be of such great risk for such weak rewards that under no definition of rationality would Saddam attempt such a thing. Saddam would have to be either an idiot or insane to supply possibly-hostile terrorists with bombs that could be traced back to him, and the current pseudo-debate over invasion due to the possibility that he might theoretically attack at some point in the future shows that he has zero reason to give the U.S. a reason to invade...

unless they're already about to do it anyway. Want to talk risk? Two words: Cornered and Desperate.

Update: Jim Henley, the target of this post, also responded to it. His point was less about the question of the rationality of what Diane proposed, and more the simple observation that deterrence doesn't usually fail as long as there is proper communication, which minimizes possible miscalculation. Personally, I think that the unspoken communication of the prior actions of the U.S. is pretty damned clear in-and-of itself. Henley, however, also makes a legitimate point in that ensuring the rational behavior of Saddam is the last thing the current administration wants (which is why the recent Iraqi invitations of inspectors from both the U.S. and U.N. is only further cementing world opinion against the U.S.)