There's a suspicion, common among conservative pundits and Arab officials, that Iran is hiding something beneath its support for Shia militias in Iraq; that it doesn't want to just destroy the Islamic State (IS), but to expand Shia control and become Iraq's de-facto suzerain. It's all part of a plan, says Henry Kissinger, to "reconstruct the ancient Persian Empire, this time under the Shia label."
This claim lies at the heart of opposition to American collaboration with Iran against IS, in the wake of the Iran nuclear accord. And yet the closer you look, the weaker it is.
For starters, Iraq isn't going to just lie down and become an Iranian puppet state. Sure, Iraqi Shias have turned to Iran for support against IS. But once the jihadist threat passes, there's no reason to believe that they won't assert their autonomy.
Though Iranian and Iraqi Shias are united by a common religious sect, they are divided by ethnicity, language and history. Iraq—once the cultural, intellectual, and political capital of the Muslim world—has always been fertile ground for Arab-Nationalism. Neither secular nor religious Iraqi Shias are likely to forget all this, and bow to an imperial Iran.
But let's assume for a moment that sectarian allegiances were all that mattered in the Middle-East—Iran still couldn't take over Iraq. Grand Ayatollah Ali Sistani, the highest authority in Shi'a Islam, lives in Iraq and he's consistently used his authority to keep Iranian influence in check.
It was Sistani's call to arms which spurred the creation of the Shia militias, and he's demanded since then that that the forces remain under Iraqi state control. That's why, when Iraqi Prime Minister Haider al-Abadi ordered the militias out of Tikrit, they listened— even though many of them had close ties to Iran, and perceived the move as an American imposition.
What's more, Sistani responded sharply through his representative when an ex-Iranian official implied that Iran and Iraq were one and the same. He thanked Iran for its military assistance, but maintained that Iraqis will not "ignore our identity and independence."
That ex-official, unsurprisingly, was put on trial in Iran. The Islamic Republic can't afford to publicly contradict Sistani, because its legitimacy at home and abroad is rooted in Shia Islam. Hence, so long as Sistani and his clerical circle refuse to embrace the "Persian empire," they'll remain a bulwark against Iranian hegemony in Iraq.
For its part, Iran likely knows that it'll never control its neighbour—and frankly, it doesn't really need to.
Iran's principal interest is in making sure Iraq becomes an ally, and not an existential threat. The memory of the Iran-Iraq War—the famine, the chemical weapons attacks, the million dead—is still burned into the collective psyche of Iranians. Since the 2003 US invasion, Tehran has sought to make sure that the new Iraqi state will not be similarly bellicose.
And for that, Iran doesn't need an iron grip on Iraq. All it needs is stability, and a chance to let sectarian allegiances and its highly diverse economy tie the two countries together. But first, Iran needs to keep the Islamic State from tearing Iraq apart.
Ergo, Iran supports Shia militias. Crucially, this means that Iran also has an interest in making sure Iraq's Sunni minority has a stake in the government, so they don't turn to IS. Iran has its own Sunni minority to worry about, and the last thing officials in Tehran want is for IS to inspire an insurgency within their borders.
Yes, Iran backed the regime of Nouri al-Maliki, whose sectarian policies marginalized Iraq's Sunnis and helped give birth to the jihadist threat. But so did Obama. And what Iran hawks conveniently leave out of this narrative is that Iran's eventual support for Abadi was what pushed Maliki out of power, when it became clear to everyone that he was the problem.
American and Iranian interests are incredibly close in Iraq, and their conventional capabilities are remarkably complementary. Iran-backed militias lack the ability to bomb protected IS targets from the air. The US has bombs in droves, but no boots on the ground to achieve its objectives— at least, not while the Iraqi army remains depressingly incompetent.
Indirect US-Iran collaboration brought victory in Tikrit; it could do the same in Mosul and Ramadi.
Right now, the US has refused to continue its airstrikes if Shia militias take part in either battle. This is understandable, given the militias' record of atrocities against Sunni populations. But instead of proscribing militia-involvement altogether, the US should ask Iran to pressure the militias they finance into good behaviour— which the militias have already exhibited, for the most part, when they escorted thousands of Sunni families back home to Tikrit.
Those who categorically oppose even trying to cooperate with Iran are at worst blindly-ideological and at best ignorant of history. According to James Dobbins, Bush's special envoy to Afghanistan in 2001, Iran provided critical intelligence and military support to the US military as it fought against the Taliban. Iranian diplomats also helped the US craft and put into place the post-Taliban democratic constitution.
Who was the head of Iran's National Security Council at that time? Current President Hassan Rouhani. Who sat across the table with Dobbins, working on that constitution? Iran's current foreign minister, Javad Zarif.
The fight against the IS has stalled. The group continues to occupy a third of Iraq. It has added chemical weapons to its arsenal. Cooperation between Iran and the US is the best chance for both sides to break the current stalemate. To rule it out altogether, as some would have us do, is not just irrational—it's dangerously irresponsible.