Iran’s supreme leader crushed internal threats during more than three decades in power. Ayatollah Ali Khamenei entrenched the system of rule by Shiite Muslim clerics.

By Andrew MacAskill, Federico Maccioni and Pesha Magid LONDON/DUBAI (Reuters) -Israel's strikes on Iran's nuclear installations so far pose only limited risks of contamination, experts say. But they warn that any attack on the country's nuclear power station at Bushehr could cause a nuclear disaster.

Much of the world views Iran’s nuclear program with alarm, and experts say its stockpile of highly enriched uranium has grown fast.