US/Iran puzzle 2

Abu Aardvark posts about a Saudi newspaper article that seems to shore up Bhadrakumar's theory, that I posted about previously, that the US/Iran confrontation may be moving towards negotiation. The Saudi article says that Iran and the US are cooperating to take Sadr out, and that Maliki and the Badr militia are attacking at Tehran's bidding.

This may or may not be true of course, but if so, I wonder if the Iranians are making a strategic error. Sadr seems to be the only Shiite leader that really has the support of the masses, the rest depend on patronage and outside help to get their business done, and at the end of the day their soldiers might not be willing to fight and die to advance US/Iranian interests. If the US does a turn around and attacks Iran, how willing will the Iraqi army/Badr brigade be to counterattack in Iraq? The Mahdi army may not be the best equipped and trained out there, but they've shown that they are willing to fight. If the Iranians follow the Americans in blindly backing their guys, no matter what the situation on the ground is, they could risk losing an effective deterrent to a US attack.