Bill Roggio: 599 fighters from al-Sadr's militia have been killed in the past 7 weeks

Bill Roggio has some info which might give a clue why al-Sadr capitulated to the Iraqi government last week:

A total of 599 Mahdi Army fighters have been confirmed killed in and around Sadr City since March 25, according to numbers compiled by The Long War Journal.

Major clashes have ended but the fighting has not halted. Apparently they are regrouping in Western Baghdad to deflect attention from Sadr City. Hat tip: LT Nixon