After a few weeks or months, they’ll return to murdering and terrorizing, hoping they’ll have support from the people again for all the good deeds they had done. Kill them all now while they’re on the ropes.
Nah. Al-Sadr is ready to become part of the Iraqi establishment. He's been positioning himself for this for a while. There are still some die-hards in his organization, but he's marginalized them to the point where the Iraqi and US forces will be able to take them out for him, wihtout any real negative consequences to his prestige and influence.
That's the way warfare works in the Orient- half the time, you win wars by getting your opponents to join your side.