The long-feared regional war between Shi’ites and Sunnis may be closer than ever. The Washington Post analyzes the rise of ISIS (sometimes called ISIL) in Syria and Iraq, which didn’t only grow organically in the vacuum left by the American withdrawal from Iraq. While the governments of Saudi Arabia and Kuwait oppose ISIS, their subjects have helped build it and may end up threatening to rewrite the political map of Southwest Asia:

As Sunni jihadists have pushed from Syria deep into Iraq, making startling gains that are now threatening Baghdad, they are highlighting the increasingly uncomfortable position of Persian Gulf states that have backed Syria’s predominantly Sunni rebels.

Officially, Iraq’s southern neighbors, Saudi Arabia and Kuwait, oppose groups such as the Islamic State of Iraq and Syria (ISIS), which captured advanced weaponry caches and forced a dramatic retreat of government security forces across northern Iraq this week.

But citizens in Saudi Arabia and Kuwait have quietly funneled vast sums of money to and joined the ranks of ISIS and other jihadist groups fighting Bashar al-Assad’s regime in Syria over the past two years, analysts and U.S. officials have said.

Saudi Arabia’s King Abdullah has ignored the conflict, just as he has ignored the Nouri al-Maliki government for the last several years. So too has Kuwait, the emirate rescued by the US after Saddam Hussein’s attempt to forcibly annex it to Iraq, and the reason why the US was involved in Iraq in the first place. That leaves Iran to come to Maliki’s rescue, and further exacerbates the millenia-old conflict between the Sunni and Shi’a branches of Islam in the region.

Now Iran is suggesting that their nation should partner with the so-called “Great Satan” — the US — to defend Baghdad and what’s left of Iraq:

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.

Officials say Iran will send its neighbor advisers and weaponry, although probably not troops, to help its ally Prime Minister Nuri al-Maliki check what Tehran sees as a profound threat to regional stability, officials and analysts say. …

Tehran is open to the possibility of working with the United States to support Baghdad, the senior official said.

That move would not only make the Saudis and Kuwaitis more hostile to Maliki, but also more hostile to the US. The outreach to Iran over the last year by the Obama administration has already perplexed and angered them, and they worry that the US might be thinking of shifting alliances to the Shi’ites in order to disentangle itself from the responsibilities of containing Tehran’s nuclear ambitions. A military alliance on behalf of the Shi’ites to salvage the debacle in Iraq might not have that intention, but that’s how it will be perceived.

In Baghdad, meanwhile, the city’s defense will rely on Shi’ite mobilization, further highlighting the sectarian divide:

Hundreds of Iraqis converged on volunteer centers across Baghdad on Saturday in response to a call by Iraq’s highest Shiite cleric to fight back against a Sunni jihadist group making rapid gains across the north.

Iraqi Shiite volunteers were responding to Ayatollah Ali al-Sistani, who on Friday issued a rare call to arms to the nation’s Shiites, setting the stage for sectarian war, local media reported.

Satellite channel Sky News Arabia broadcast footage showing dozens of Iraqis gathering at centers in Baghdad to volunteer in the fight against ISIS.

Shiite religious volunteers would partially plug the ranks of Iraq’s decimated security forces, after jihadists from the al-Qaeda-inspired Islamic State of Iraq and Syria (ISIS) rapidly seized ground from the northern city of Mosul to a town just 60 miles north of Baghdad this week in a stunning military advance that threatens to divide this fragile nation.

Only “hundreds”? [See update below.] If all Sistani can summon to face down ISIS while it’s 50 miles out and closing in on Baghdad is a few hundred fighters, then both Sistani and Maliki may well be doomed, at least in the capital. Iran may well have to commit troops to just provide a retreat corridor to Basra and allow the Shi’ites in Iraq to organize better for a counter-offensive, if and when American help ever arrives.

Even if they do manage to hold Baghdad, it’s going to be a very different place if Sistani succeeds:

Baghdad residents said those signing up are largely members of Shiite militias notorious for bloodletting during the darkest days of Iraq’s civil war, raising fears of a return to levels of sectarian violence that could tear the country apart.

That sectarian violence has already arrived. After the Sunni-extremist ISIS sweep and brutal occupation, it’s going to be almost impossible to put Iraq back together as a multi-cultural democratic republic.

The Kurds are well aware of these consequences. They’re fighting ISIS in the north, as this AP video shows, and perhaps staking out their own turf for independent statehood after decades of being bottled up by successive Iraqi monarchs, dictators, and republics:

AP Television News footage showed Kurdish fighters, known as peshmerga, driving out militants who had taken over an army outpost some 15 miles west of the oil city of Kirkuk. The position had earlier been abandoned by Iraqi army troops. Long coveted by the Kurds who have a self-rule region in northern Iraq, Kirkuk fell under the control of the peshmerga this week after Iraqi army forces left. …

The latest bout of fighting, stoked by the civil war in neighboring Syria, has pushed the nation even closer to a precipice that could partition it into Sunni, Shiite and Kurdish zones.

The Turks won’t be happy about that — they have been fighting Kurdish separatists for decades on both sides of the border. On the other hand, if the alternative is ISIS reaching their borders, the Turks might have to reconsider their previous opposition to Kurdish statehood.

Update: I got my ayatollah scorecards mixed up in the first version of this post. Ali al-Sistani was the Shi’ite cleric that attempted to work with the US; it was Moqtada al-Sadr who went to war intermittently with the US, who later semi-retired from politics. Since we’re on that subject, though, Sadr hasn’t been silent either:

Powerful Shiite cleric Moqtada al-Sadr, who led the once-feared Mahdi Army militia, on Wednesday called for the formation of units to defend religious sites in Iraq.

Sadr said in a written statement that he was ready “to form peace units to defend the holy places” of both Muslims and Christians, in cooperation with the government.

His call came after Prime Minister Nuri al-Maliki said the government would arm citizens who volunteer to fight militants, following the fall of Iraq’s second city Mosul and a swathe of other territory to jihadist Sunnis on Tuesday.

But Sadr’s involvement in the formation of such units would almost certainly be unacceptable to Iraq’s Sunni Arab minority, members of which are also deeply mistrustful of Iraq’s Shiite-led government.

He’s also making that call from Beirut, not Baghdad. Meanwhile, the Washington Post profiles Sistani for a reminder of his influence:

Sistani emerged from relative passivity after Saddam Hussein’s ouster by U.S. forces in 2003 to become a vocal religious and political guide for Iraq’s suddenly empowered Shiite masses.

His words Friday marked a radical departure for a man who has played a powerful hand in shaping Iraqi politics, but has typically urged Iraqi Shiites to resist provocation to sectarian bloodshed.

And as the most powerful religious authority in Iraq, Sistani’s words were likely to find support among the country’s Shiites and political leaders, who are desperate to hold on to power and have a fleet of well-trained Shiite militias ready to act.

My apologies for confusing the two in my original post, and thanks to Calbear for correcting me by e-mail.