Terrorists aren't stupid. Neither are the nations that support them, either directly or at arms length. If an atomic weapon were used on US soil, or that of one of our close allies, they know our current administration would probably shoot first and ask questions later. Any Islamic or even anti-US government that didn't fall all over itself trying to proove that it was not responsible and committed all of its resources to finding out who did would come out on the losing end of that tactic.

That said... tough call on letting them have nukes. I think that in terms of "global stanility" it's less alarming than India and Pakistan having them. Granted, neither of those nations is aggressive to the US, but they HATE each other, and they're a border skirmish away from being the Powder Keg of the 21st century. Iran on the other hand, has just had its arch rival eliminated, and has no real enemy aside from us, though I doubt they would overtly attack us or even hand over a bomb to Al Qaeda. They know that dying ain't much of a way to make a living, boy. I say we turn it around- provide support for their nuclear program and demand concessions in other areas from THEM. Basically, the question you didn't ask that I think might just be more important Paul, is do we along with the leaders of Europe have the right and justification to demand Iran remain without nuclear weapons? As you said, they are breaking no international laws or treaty agreements, only a mandate by our government that says we think we should get to decide who does and doesn't have nukes.