Right on cue, the Mahdi Army is fighting the occupiers and their surrogates in the streets
. It looks as if a crackdown on the group, probably induced by their sectarian pro-occupation antagonists in the puppet government, has brought this about. It's a real problem for the occupiers, since they know that to turn Sadr into an armed resistance leader would be it for them. They can't win against the resistance as it is, but they'd certainly lose if an alliance between the Sadrists combined themselves with it.