President Obama and UN Secretary General Ban Ki-moon at the White House today. Last week the UN Security Council approved the Iran nuclear deal by a 15-0 vote. (Jonathan Ernst / Reuters) The latest set of indicators: 1. Logic. Graham Allison, who originally made his academic reputation with Essence of Decision, his study of the negotiations that averted a U.S.-Soviet nuclear catastrophe in 1962, has another installment in his series of Atlantic essays on the details and implications of the nuclear agreement with Iran.