Then there is the case of Iraq. Saddam Hussein failed to achieve nuclear capability, lost a war to the United States that left him partially disarmed, and then despite his weakness was subsequently toppled on charges of possessing W.M.D. that mostly did not exist. Any authoritarian regime observing that history might reasonably conclude that nuclear weapons should be sought and never be given up …

… Especially since our next president decided to tacitly confirm that lesson, by pursing regime change in Libya after the Libyan dictator had agreed to close down his own W.M.D. program. The spectacle of Qaddafi getting murdered by a Libyan mob, however roughly just, was also an object lesson in the downsides of believing that the Americans will care about a W.M.D. deal if the opportunity arises to remove you afterward.

Despite our official commitment to nonproliferation, then, the revealed preference of our foreign policy elite is often for other priorities — NATO expansion, humanitarian intervention, regime change.