Iran: The Logic of Deterrence by Christopher Layne

Still, although a nuclear-armed Iran is not a pleasant prospect, neither is it an intolerable one. Tehran won’t be the first distasteful regime to acquire nuclear weapons. The United States has adjusted to similar situations in the past and can do so this time. Rather than preventive war and regime change, the best policies for the U.S. with respect to Iran are the tried and true ones: containment, deterrence, and diplomatic engagement.