Further it's predominantly lead by the Iraqi's with the U.S. backing them up.
It's to further solidify the sovereignty of the Iraqi government so that the people can hopefully feel like things are getting under a more centralized control & security. Which is a good thing.

This is ultimately contingent on Al Sadr continuing the cease fire.
Personally I think that the elected contingent of Al Sadr's presence in the government put on a show of being offended when the Iraqi military did their crackdown but I suspect in reality it was a show for the overall Al Sadr militia while covertly they were glad that the government was cleaning up some of the more criminal elements that hide under the banner of either Al Sadr's militia or Al Qaeda, depending on whatever element is strongest in a specific community.

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The crows seemed to be calling his name, thought Caw.
- Jack Handy