When Ayatollah Ruhollah Khomeini, the charismatic leader of Iran’s Islamic revolution, died in 1989, hundreds of thousands of mourners packed the streets, fearful of what might happen next. For more than six months Iranians have been demonstrating en masse, chanting death to Ayatollah Ali Khamenei, the founder’s ailing successor as supreme leader. In 1989 the triumvirate, including a son of …