You know what's great fun to do if you're on, say, a flight from Chicago to New York and you're getting a little bored? Why not play being President Ahmadinejad? Stand up and yell in a loud voice, "I've got a bomb!" Next thing you know the air marshal will be telling people, "It's OK, folks. Nothing to worry about. He hasn't got a bomb." And then the second marshal would say, "And even if he did have a bomb it's highly unlikely he'd ever use it." And then you threaten to kill the two Jews in row 12 and the stewardess says, "Relax, everyone. That's just a harmless rhetorical flourish." And then a group of passengers in rows 4 to 7 point out, "Yes, but it's entirely reasonable of him to have a bomb given the threatening behavior of the marshals and the cabin crew."
That's how it goes with the Iranians. The more they claim they've gone nuclear, the more U.S. intelligence experts -- oops, where are my quote marks? -- the more U.S. intelligence "experts" insist no, no, it won't be for another 10 years yet. The more they conclusively demonstrate their non-compliance with the IAEA, the more the international community warns sternly that, if it were proved that Iran were in non-compliance, that could have very grave consequences. But, fortunately, no matter how thoroughly the Iranians non-comply it's never quite non-compliant enough to rise to the level of grave consequences. You can't blame Ahmadinejad for thinking "our enemies cannot do a damned thing."
As Mr. Steyn points out, the Iranian braggadocio should be enough to motivate us to substantial action.