Iraq is in political crisis, less than a week after the formal end of direct US involvement in the war there. Prime Minister Nouri al-Maliki has brought terrorism charges against Sunni Vice President Tareq al-Hashemi, is moving to oust Sunni Deputy Prime Minister Saleh Mutlaq from his position, and has threatened to take away the nine cabinet seats held by the largely Sunni Iraqiyya bloc and replace them with members of his own Shiite governing coalition.

Mr. Hashemi, a Sunni Islamist who heads the Iraqi Islamic Party, is a member of the Iraqiyya bloc, and had a number of close family members murdered during Iraq's civil war. Hashemi had some ties to Iraq's insurgency during the worst of the fighting (when former Monitor reporter Jill Carroll was released by her Sunni kidnappers in 2006, she was dropped off in front of his office) but has worked as much as any on his side of the fence to forge sectarian reconciliation in the years since.

But now he has fled to Kurdistan, where he's being shielded from his arrest warrant. In a televised news conference today, Mr. Maliki threatened the Kurdish north with "problems" if they don't hand over Hashemi.

Iraqiyya's legislators have walked out of parliament while the group attempts to hang on to its cabinet seats, which are the valves of political patronage in the new Iraq. While Maliki's threat to simply appoint his own ministers is unconstitutional, the Constitution has been increasingly ignored when inconvenient.

With Iraqiyya being politically hounded, a return to open civil war in Iraq is a real possibility. The group effectively represents Sunni interests in the country. Sunni voters turned out enthusiastically in 2010 after past electoral boycotts, and the group was in effect an experiment in whether they could gain a real political voice in the country through the ballot box. The failure of that experiment will send a worrying message.

How did we get here? Last year, Maliki and fellow Shiite politicians deftly outmaneuvered Iraqiyya to hold on to power after elections. The new prime minister assured his erstwhile American benefactors and Iraq's Sunni Arabs that power sharing arrangements would be found to mollify fears that a new tyranny of the majority was emerging in Iraq. That's one reason three "vice president" posts were created, including the one Hashemi now holds.

Sure, Iraqiyya had won a plurality of seats in the new parliament and so by rights should have been allowed to form Iraq's government. But Maliki had simply cobbled together a stronger coalition, all part of the democratic game. Fears that Shiite Islamists will lord it over Iraq's Sunni Arab minority (about 40 percent of the population)? Don't worry, Maliki said. I'm creating a super-committee to share power to give Iyad Allawi (the former Baathist who leads Iraqiyya) a meaningful seat at the table.

The powerful defense and interior ministries? Maliki said: Don't worry, we'll set those aside for now but I'm sure a reasonable compromise will be worked out to place respected figures in those posts who will quell concerns they're being transformed into tools of political oppression.

But almost exactly a year after Maliki's government was formed, defense and interior are directly controlled by the prime minister, something that is probably illegal under the new Iraqi Constitution that the US helped to write. The power sharing committee? It still doesn't exist. Sectarian tensions and fears? They have been heightened in the interim with the latest moves against Hashemi and the rest of Iraqiyaa the cherry on top.

Many in the United States continue to misunderstand what's been happening in the US-Iraq relationship for the past five years. The US desire to restore sovereignty to Iraq culminated in the 2008 Status of Forces Agreement signed by President George W. Bush that called for complete withdrawal by the end of this year. Many in the US establishment hoped that an extended stay would be worked out in the interim.

But in Iraq, the US occupation (widely described by that term there long after the US had given up governing powers) was deeply unpopular. Maliki and the Shiite Islamist politicians around him, who plotted the overthrow of Saddam Hussein and his Baathist regime from Tehran, Amman, and Beirut for decades, were eager to see the back of America's army.

After the US troop surge in 2007 helped tamp down Iraq's tragic sectarian bloodletting, and with a reconstituted Iraqi Army and police force packed with Shiites and built on the US dime, they had little use for extended US influence in the country. So Maliki refused to give President Barack Obama extended permission for a large troop presence in the country.

This was not only predictable from an analysis of Iraqi politics and the preferences of men like Maliki, it was largely unavoidable. While those involved in the partisan punditry game, like The Washington Post editorial board – which argues today that the current crisis is Obama's fault (his administration "risked just such a breakdown when it disregarded the recommendation of its military commanders that some US forces remain in Iraq to help guarantee against a return to sectarian conflict") – suggest that US troops could have remained, they don't seem aware of the difficulties involved.

To stay without explicit Iraqi permission would be in effect another reoccupation, with an Iraqi prime minister transformed from ambivalence to the US to open hostility. Without the immunity protections of the old SOFA, US troops could be seized and tried under Iraqi law, the same law being wielded against Hashemi now. What then? Another war for regime change?