The two major currents in Shia today are Grand Ayatollah Sistani's quietism and Iranian khomeinism. They are unalterably opposed to each other, one shunning direct political activity, the other wholeheartedly embracing it. This conflict, like many others had its lid kept on by Saddam's Baathist dictatorship. Iraqi quietism is probably the best vector we have to implement a firm kill as opposed to Tom Barnett's soft kill option (killing via connectivity), a scenario that I've never quite got with regards to Iran since the Iranians aren't stupid and know how to make themselves repulsive enough that they will always be able to limit connectivity sufficiently (through foreign disconnection campaigns) to maintain a grip on power.
Yet Barnett has a real point when he says:
We have Iran over the barrel but can't see the opportunity because of our strange fixation on global gun control.
Thus the solution to the Iranian problem is making the government of Iran our friend (at least to the level of friendship with France) no matter which faction is in power. But the US is singularly ill equipped to fight a religious conflict. We would tear apart our 1st amendment if we were to do such a thing. Here is where Grand Ayatollah Sistani comes in.
For his own reasons and completely independently of the US, he is the mortal enemy of khomeinism. He wants quietist Shiism to prevail. And he is winning.
In Tehran's storied central bazaar, an increasing number of merchants are sending their religious donations, a 20 percent tithe expected from all who can spare it, to Iraq's most senior Shi'ite cleric -- rather than to clerics closer to Iran's state power structure, said Jawad al-Ghaie, 48, a wholesaler of false eyelashes and nail extensions and a respected lay donor.Speaking carefully to avoid directly challenging the Iranian government, he and several fellow merchants suggested that Iraq's Grand Ayatollah Ali al-Sistani holds more spiritual sway because of his lifelong commitment to quietism. That is the school of thought that says Shi'ite leaders should stay out of government, and Sistani has stuck to it despite the great temptation to wade into the chaos of Iraqi politics.