I must recommend this excellent article on why Najaf is the battleground for the religious battle between the Sistani and the Iranian mullahs. Sun Tzu teaches that all wars depend on an economic foundation and this article explains Najaf's importance in the future economics of Iraq, especially in the religious issues that lay at the heart of terrorism. Though terrorist themselves are not religious, as such, they leverage the religious impulse among Muslims for their support. Sistani and his school of Islam teaches that this support is severely misguided, which is why his success is so important in the war on terror.