As this monograph goes to press, the nuclear agreement negotiated between Iran and the so-called P5+1-the five permanent members of the United Nations Security Council consisting of the United States, France, the United Kingdom, Russia, China, plus Germany-is the subject of heated debate within Washington. The negotiations that produced the agreement perhaps best exemplify the efforts by the Barack Obama administration to use diplomacy to address the most vexing security challenges of the day. The United States and Iran have struggled to overcome mutual hostility and distrust stemming from the 1953 coup against the Mohammad Mossadegh government and the 1979-80 hostage crisis, not to mention Teheran's use of Hezbollah as a proxy against American ally Israel. Yet despite this, the administration persisted over several years to first intensify and broaden economic sanctions against Iran, and then to engage in painstaking negotiations with an authoritarian country that routinely and methodically employs...