With only the one source, I can't quote a lot in this diary. Writing it mainly to keep the information alive. I'll take it down if I see it is superseded with more info.
The Washington Post has a story with a headline about Sadr Recalibrating his strategy.
And if you call announcing full-out war with America within the next week to month a "recalibration," it's an appropriate, but half-assed, headline.
Formally, Sadr has announced that he will not participate in the upcoming elections, because they are illegitimate while Iraq is occupied, and that some members of his following will form a military force, with the aim of driving the occupation out.
A commander of a Mahdi Army company, speaking in the face of the Iraqi government (read competing Shi'a groups) pouring tens of thousands of troops into Najaf and other Southern cities, said
...thousands of militia members have been training "inside and outside Iraq." "We believe that now the time has come for these companies to be given the green light to achieve our aims," he said.
...."From now on, there will be violent unexpected actions that will astonish the Iraqi people, the Iraqi government and even the occupation forces," he said. "Now we will be assigned to fight openly, and we will fight till the last drop of our blood."
It seems to me the vise is tightening around him, and he's going for make or break, trying to turn his opponent Shia around to unify against the US. Remember that decrease in violence? That's going to change.