Who will succeed Shia Islam’s top man?

“Allah yatawal omru: May God grant him a long life” has long been an Arabic mark of respect for the elderly. But seminarians in Iraq’s shrine city of Najaf have begun reciting it almost obsessively. Ali al-Sistani, the grand ayatollah who is the senior religious figure for the world’s 200m Shias, is 92 and fading.No one has done more over the years to keep Iraq from collapse or from turning it into an Iranian-style theocracy, though he has used his influence to veto any Iraqi leader of whom he strongly disapproves. Despite his humble way of life, he heads a multinational network worth billions of dollars and presides over the holiest of Shia shrines, visited by millions every year. Seeing no obvious successor, many Shias fear a struggle that could, as an insider puts it, be “messy, complicated and rife with division”.