Why Prime Minister Maliki Must Resign N OBODY wants another civil war in Iraq, yet events are propelling it in that direction. War can be averted only by a new political understanding among three main groups - Sunni Arabs, Shiite Arabs and Kurds - but Prime Minister Nuri Kamal al-Maliki has become too divisive to deliver it. So the United States, together with Iraq's neighbors, must press Mr. Maliki to resign so he can be replaced with a more conciliatory figure. Last week, Iraq experienced the most serious escalation of violence since 2006, when it slid into civil war. Now it risks being sucked into a catastrophic vortex of regional violence centered on Syria. America, Iran, Saudi Arabia, Turkey, Jordan and the Persian Gulf states have a rare, deeply shared interest in preventing another civil war that would benefit only militant extremists. Iraq's first civil war developed after decades of authoritarianism, warfare and devastating sanctions destroyed Iraqi society, and after the 2003 American invasion dismantled the Iraqi state without a plan for swift reconstruction. The power vacuum let sectarian tensions, latent in the long-brutalized population, explode. But by 2007 and 2008, Iraq was putting itself back together; the United States helped Sunnis battle extremists in their midst and supported Mr. Maliki, a Shiite, as he suppressed radical Shiite militias. Only by putting their trust in the political process, and turning against the extremists in their own communities, did Iraqis stem the violence. But if Mr. Maliki, who took office in 2006, had a successful first term, he has squandered the opportunity to heal the nation in his second term, which began in 2010. He has taken a hard sectarian line on security and political challenges. He has resisted integrating Sunnis into the army. He has accused senior Sunni politicians of being terrorists, hounded them from power and lost the cooperation of the Sunni community. The result: the political bargain that had sustained the fragile Iraqi state broke down. Today, resurgent terrorist groups have killed hundreds of moderate Sunnis who once fought them, and are offering others a grim chance to save their lives - by "repenting" and joining the extremists. Meanwhile, Vice President Tariq al-Hashimi, a Sunni, remains in exile, having fled and then been given a death sentence in absentia on charges of terrorism. Similar moves to charge Finance Minister Rafe al-Essawi, a moderate Sunni, led to the protests that have now engulfed Iraq's Sunni heartland and alienated other communities. An army attack on a protest encampment last week brought only wider violence. Relations between Mr. Maliki and Iraqi Kurds, who are largely self-governing, also rest on a knife's edge after a year in which territorial disputes almost led to military confrontation. Even as the Kurds deployed security forces to the disputed region of Kirkuk, they negotiated for concessions from the Maliki government. This week, Kurdish sources reported the signing of a new deal, but after all the broken promises there is little reason to think it will last. Given the two-year-old Syrian civil war escalating next door, a sectarian crisis and political collapse in Iraq would be a disaster at the worst possible time. It would blur the boundaries between the two conflicts, bring additional misery to Iraq and pose enormous challenges for Iraq's neighbors and the United States. That specter is so frightening, it just might be possible to stave off - if Iraq's neighbors and the United States can recognize, and decisively act on, their shared interest in maintaining Iraq's stability and territorial integrity. Iran and the United States, despite their deep divisions over the Syrian government and the Iranian nuclear program, can cooperate quietly, as they did in 2001 against the Taliban in Afghanistan. Saudi Arabia, Qatar and Turkey could lend their strong voices; they, too, want good relations with a stable, prosperous Iraq, and have their hands full aiding Sunni rebels in Syria. It is true that Iran supported militants in Iraq to frustrate the American occupation, but the withdrawal of American troops has changed such calculations. Now, in Iraq, Iran has a market for its goods and a friend to relieve its isolation. For its part, the United States is less concerned about Iran's current role in Iraq than about the possible empowerment of extremist militants during a civil war. If all of these countries could persuade Mr. Maliki to resign, it would give moderate Sunnis a symbolic victory and dampen extremist influence in their community. That, in turn, could show all Iraqis that change can be achieved through politics, rather than war. Iraq's parliamentary democracy could survive a resignation. It is normal for a prime minister to step down and be replaced by another figure elected by Parliament. There are other capable Shiite politicians who could recruit and lead a national-unity government. A decade after Saddam Hussein's fall, violence threatens to overwhelm Iraq. Getting Iran, Saudi Arabia, Qatar and Turkey to cooperate with the United States on a new political bargain there, with Mr. Maliki out of the picture, won't be easy, but it's essential to save Iraq. Nussaibah Younis is a research fellow in the international security program at the Belfer Center for Science and International Affairs, Harvard Kennedy School.