Iran's supreme leader's second son, Mojtaba Khamenei, has emerged as one of the driving forces behind the government's crackdown, diplomats and observers said. Mojtaba is an ally of Mahmoud Ahmadinejad, the disputed president, and was credited with winning his father's endorsement for the then Tehran mayor in the 2005 elections, leading to Ahmadinejad's shock second round victory. Mojtaba is an austere figure, generally seen as more hardline than his father and has become a gatekeeper for access to the beit-e-rahbari, the supreme leader's home, and the supreme leader himself. According to some Iran analysts, Khamenei, 70, is manoeuvring to position...