Does this mean that our only option is war? Yes, although an air campaign targeting Iran's nuclear infrastructure would entail less need for boots on the ground than the war Obama is waging against the Islamic State, which poses far smaller a threat than Iran does.

Wouldn't an attack cause ordinary Iranians to rally behind the regime? Perhaps, but military losses have also served to undermine regimes, including the Greek and Argentine juntas, the Russian czar and the Russian communists.

Wouldn't destroying much of Iran's nuclear infrastructure merely delay its progress? Perhaps, but we can strike as often as necessary.