Ayatollah Ali Khamenei has spent almost four decades as Shi'ite Iran's supreme leader building a regional power to rival the Sunni states across the Gulf and implacably hostile to the U.S. and Israel - while crushing repeated unrest at home.

In connection with the Israeli air campaign, the Mossad, Israel’s foreign intelligence service, has been operating on Iranian soil and targeting senior Iranian nuclear scientists and military officers in an attempt to shatter the Iranian military’s chain of command.