There must have been some great minds along the Larry Wilkerson lines restraining the US military commanders from dealing with this noisy self-appointed holy man when his personal militia began acting up in the early days of the US occupation. al-Sadr actually led uprisings against US forces already in 2004 in Najaf, but was saved by taking shelter in a mosque while Grand Ayatollah Ali Sistani negotiated to save him.
US policy in the War on Terror has been too often influenced by namby pamby-ism and too frequently has featured undue deference to the bigotry and superstitions of Mohammedanist fanatics. Can anyone imagine the US military command supplying copies of Mein Kampf to Waffen SS prisoners during WWII, and requiring POW camp guards to treat the Holy Bible of Nazism with respect? Would we have allowed some particularly belligerent Gauleiter in Bavaria to retain his own Werwolf resistance militia? Weakness in dealing with these kinds of troublemakers only leads to greater insolence, and further and worse trouble down the road.