It’s tempting to point to the March 7 elections in Iraq as a sign that an American-fostered democracy has put down roots in that shattered nation. But the reality is different. Despite signs that many Iraqis are disenchanted with ethnic and sectarian politics and long for a secular and nationalist Iraq, the vote still broke sharply along communal lines, leaving simmering and potentially violent divisions unhealed. Virtually all Kurds voted for Kurdish parties in the three northern provinces and in the multiethnic border provinces that straddle the Arab-Kurdish line. Nearly all Sunnis voted en bloc for the coalition led by former Prime Minister Iyad Allawi, a secular Shiite who appealed broadly to disenfranchised Sunnis, supporters of the former Baath Party, and Arab and Iraqi nationalists opposed to Iran’s influence. And the vast majority of Shiites, who make up about 60 percent of the electorate, voted either for Prime Minister Nuri Kamal al-Maliki, who leads the secretive Shiite religious Dawa Party, or for an even more fervent Shiite religious bloc, the Iraqi National Alliance (INA), put together in Iran last year, whose leaders include Muqtada al-Sadr’s movement, the Islamic Supreme Council of Iraq, and Ahmad Chalabi.

Not only is Iraq still split along communal lines; the aftermath of the election has renewed concerns that those divisions could escalate into violence, even civil war, during the coalition-building, likely to drag on for many months. With nearly all the votes counted, the rival blocs led by Maliki and Allawi are evenly matched, with each expected to get about ninety seats in the 325-member National Assembly. The Kurds will accumulate about fifty seats, and the Shiite-religious INA perhaps seventy.

In a more politically mature nation–say, one whose polity was not destroyed by US invasion, subsequent insurgency and then several years of horrendous civil war–the politicians who lead those blocs could form a coalition. But in Iraq a peaceful outcome is not at all certain. The Kurds and the INA have powerful paramilitary forces, and Maliki has shown he is prepared to use the security forces to do his bidding. And Sunnis, many of whom supported the 2003-07 insurgency, could rebel again. Even if the worst is avoided in the immediate future, Iraqi politics is a Rubik’s cube of which it’s hard to imagine a stable, ruling alliance forming the necessary majority in the National Assembly.

Iraq poses a difficult challenge for the United States, and President Obama faces unpalatable choices. At best, the next Iraqi government will be fragile and plagued by terrorism and violence. At worst, the country will fall back into a three-way civil war. Although the United States is mostly to blame for Iraq’s tragic predicament, it’s far too late for Washington to try to regain its role as post-2003 power broker. Whatever problems Iraq faces are going to have to be solved, first and foremost, by Iraqis themselves. The story of Iraq since 2003 contradicts Colin Powell’s oft-cited Pottery Barn rule: we broke it, but we don’t own it.

Obama must also resist calls from various quarters in Washington to slow or reverse the drawdown of US forces. Under the terms of the Status of Forces Agreement, signed during the waning months of the Bush administration, all US forces must leave Iraq by the end of 2011. Upon taking office, Obama added that he would reduce US forces to no more than 50,000 by this August, and he reconfirmed the plan to withdraw the rest by the end of next year. But Thomas Ricks, a former journalist now at the Center for a New American Security, has suggested that Washington must plan to "keep 30,000 to 50,000 [US] service members in Iraq for many years to come," and his view is echoed by conservatives, neoconservatives and Republican politicians who’d like nothing better than to blame Obama if Iraq unravels in the future. In particular, Senator John McCain, who was a principal proponent of the 2007 "surge," called on Obama to "be flexible in implementing the withdrawal of US forces," making it conditional on the "high performance of Iraqi’s government."

As recently as this year’s State of the Union address, Obama reiterated his plan to remove US troops, and it would be foolhardy to change plans now. Whatever stability there is in Iraq depends on the widespread conviction that the occupation is coming to an end, and no Iraqi government could turn around and invite US forces to stay. Besides, Obama was elected in part because of his promise to bring the troops home, and it would be politically costly to maintain a large US force in Iraq–a problem made even more difficult because the Pentagon wants those troops for the growing US presence in Afghanistan.

Not that Washington should just walk away. Much of what happens in Iraq is the result of involvement by Iraq’s neighbors–not only Iran but Saudi Arabia, Jordan, Syria and Turkey. As troops depart and US leverage decreases, Iran’s power in Iraq is likely to rise, and other neighbors may step up their support of favored parties. The Obama administration, along with the UN, is dutybound to use vigorous regional diplomacy with Iraq’s neighbors to help reduce the likelihood of civil conflict. Above all, that means Obama must redouble efforts to reach an understanding with Iran. No Iraqis, regardless of their politics, want their country to become a battlefield between Washington and Tehran over Iran’s nuclear program and its role as a regional power in the Persian Gulf. But that’s exactly what could happen, especially if an overtly pro-Iranian government emerges in Baghdad. If there is any hope of long-term stability and development for Iraq, it will depend to a great extent on an understanding between the United States and Iran that neither party intends to fight a proxy war on Iraqi territory.