I’m not sure what “cooperation” means here, exactly. Are we talking about loose coordination, with U.S. jets targeting ISIS supply lines to make things easier for Iraqi troops on the ground? Or are we talking about Martin Dempsey and Qassem Suleimani on the phone together, plotting coordinated air-ground action on the front lines between the USAF and IRGC?

Really excited about a formal partnership with Shiite terrorists to defeat Sunni terrorists. Onward to the future!

Shi’te Muslim Iran is so alarmed by Sunni insurgent gains in Iraq that it may be willing to cooperate with Washington in helping Baghdad fight back, a senior Iranian official told Reuters.

The idea is being discussed internally among the Islamic Republic’s leadership, the senior Iranian official told Reuters, speaking on condition of anonymity. The official had no word on whether the idea had been raised with any other party…

“We can work with Americans to end the insurgency in the Middle East,” the official said, referring to events in Iraq.

“We are very influential in Iraq, Syria and many other countries.”

Supposedly Iran’s willing to send only weapons and advisors, like 150 Quds Force troops, to Iraq right now, but some U.S. officials think Baghdad’s going to be overrun if something doesn’t change quickly on the ground. (“The Green Zone is going down.”) If Tehran was willing to send IRGC and Hezbollah muscle to Syria to help Assad, they’ll eventually muscle up to stop ISIS from pushing to the Iranian border too. Maliki still has Shiite militias in Baghdad and southern Iraq he can call on — they started to remobilize months ago as ISIS advanced south — but ISIS has evolved into a professional fighting force, now equipped with U.S. weaponry confiscated in Mosul. How long would the militias last against 12,000 ISIS guerrillas? Time for Iran to fight a two-front war of its own.

One thing that interests me about the rise of ISIS is how it represents yet another misjudgment by Al Qaeda about its prospects in Iraq. They tried to turn Anbar province into a base during the U.S. occupation but ended up alienating the locals with their brutality, which led to the Awakening, which in turn kept them from putting together the sort of broad advance we’re seeing right now. One of the lessons they seem to have learned from that was that they can’t afford to be quite as savage with the locals as they might like, culminating in AQ actually kicking ISIS out of its coalition in Syria due in part to that group’s even more insane brutality. Fast-forward four months and not only is ISIS as vicious as ever, leaving decapitated Iraqi troops by the side of the road and forcing captives to dig their own graves before having their throats slit, they’ve actually formed a coalition of their own with some of Saddam’s Baathist henchmen and leftover Sunni insurgents who hate Maliki’s government. The NYT has an eye-popping story today about some Iraqi Sunnis choosing to return to Mosul, now occupied by ISIS, simply because they’ve concluded that anything would be better than rule by the Shiite government in Baghdad at this point. That’s how disastrous Maliki’s sectarian approach to government has been for Iraq. Zawahiri and Al Qaeda must be mystified, though. First they were too brutal and failed; now an even more brutal group is threatening to take over the country, with Sunni support. That’s more a function of bad timing than bad strategy, with ISIS exploiting a political and security vacuum left by America’s departure, but oh well.

Exit question: Which dumb piece of conventional wisdom will the foreign-policy establishment be pushing soon vis-a-vis Iraq? The idea that a peace deal between Israel and the Palestinians might help solve this crisis? Or the idea that there are “moderates” within ISIS whom we should reach out to for peace talks?

Update: And there you have it.

BREAKING: #Iran Revolutionary Guards are fighting INSIDE Iraq in support of Baghdad govt against ISIS, Iraq official tells CNN

— RAGreeneCNN (@RAGreeneCNN) June 13, 2014

Ayatollah Sistani, Iraq’s highest-ranking Shiite cleric, also put out the call today for Iraqis to fight ISIS. Sunni/Shiite civil war, dead ahead.