The death of Osama bin Laden highlights what a difference a decade makes, even for a country as seemingly unchanging as the Islamic Republic of Iran. Ten years ago, in the aftermath of the September 11 attacks, Iranians and their government responded with sympathetic outrage. Tehran was the scene of spontaneous candlelight vigils by ordinary Iranians and a temporary suspension of the weekly chants of “death to America” by its official clergy. An array of Iranian officials, many with reformist political leanings, offered seemingly heartfelt condolences to the American people, and even the hardest-line elements of Iran’s leadership briefly summoned the moral decency to denounce al Qaeda, its leader Bin Laden and the use of terrorism against Americans. Over the course of subsequent weeks and months, Tehran provided crucial logistical assistance to the U.S. campaign against the Taliban and cooperated closely with Washington in establishing a new Afghan government. For a short time, the prospects for ending the bitter estrangement between the two countries and for Iran’s return to the community of nations seemed for the first-time truly conceivable.