While the news media have covered every twist and turn in the negotiations over a constitution, it has largely ignored the most important development in Iraq since the January 2005 election – the emergence of a sectarian civil war between Sunnis and Shiites.

The beginning of Shiite violence against Sunnis by Shiite militias, with tacit government approval, raises a new issue of central importance to U.S. policy.

For many months, most pundits and political figures have been saying that a withdrawal before the country was stabilized would result in a civil war. But since the Shiites won the election and began taking over the government, have increasingly turned to extralegal violent repression against Sunnis.

The Shiites have now been emboldened to seize a Sunni mosque in Baghdad. Even worse, Shiite paramilitary units have begun striking in Sunni neighborhoods, kidnapping, torturing and killing Sunnis. Last week Shiite militia deposed the Sunni mayor of Baghad and replaced him with one of their own members, despite the fact that the Sunni population of the capital is much larger than its Shiite population. None of this is being acknowledged by the Iraqi government or the Bush administration. But Iyad Allawi, the U.S. choice as interim Prime Minister a year ago, recently warned that Iraq is “practically in stage one of a civil war….”

Acknowledging that Iraq is sinking into sectarian civil war opens up a new line of arguments for withdrawal: The United States should not put its troops in a situation of where they are openly intervening on one side in a sectarian civil war. That argument leads logically to the demand that the United States should stop trying to kill insurgents who are arguably fighting for Sunni political interests as well as against the occupation on behalf of the Shiites.

The sectarian civil war is a logical consequence of the Administration’s tacit alliance with the Shiite majority against the Sunni minority. It happened because the Bush administration bowed to the Shiite cleric, Sistani, who threatened to paralyze the country if the United States didn’t agree to the January elections which brought militant Shiite leaders to power.

The true costs of the Bush administration’s alliance with the Shiite government against the Sunnis must be spelled out. It encourages the Shiites to carry out extralegal repression against Sunnis who aren’t sufficiently compliant. It has also inflamed Sunni passions against both the U.S. forces and the Shiites. Finally, it has solidified Sunni support for the insurgency, as dramatically demonstrated by the nearly total boycott of the January elections within Sunni strongholds. And no Iraqi political system can be stable, much less evolve into a liberal democracy, while such a sectarian war is being fought.

The strategic blunder of the U.S. alliance with the Shiites in the Iraqi civil war recalls the U.S. intervention in the 1983 Lebanese civil war between Christian and Shiite Islamic factions, in which U.S. forces fought on the side of the Christian minority. Colin Powell recalled later opposing what he called “America sticking its hand into a thousand year-old hornet’s nest.”

The administration has already conceded that it cannot defeat the insurgents, and it expects the war to go on for many more years. Secretary Rumsfeld implied as much when he told a press conference in late June that “insurgencies tend to go on five, six, eight, ten, 12 years.” Thus the administration’s policy ensures that the al Qaeda terrorists will continue to have the use of Iraq for years to come.

Once the problem is viewed as intervention in a sectarian civil war, a “responsible” exit strategy becomes an option. That means using U.S. influence over the Shiites to encourage a resolution of the war rather than a long-term, bloody sectarian conflict. The U.S. has plenty of leverage to use on the Shiite government to attain negotiations. The Shiite government is extremely dependent on the U.S. military presence and $20 billion dollars of U.S. reconstruction funds.

A pro-democratic Sunni former minister in the Interim Government who has had had extensive discussions with a number of leaders of major insurgent groups says they are willing to negotiate to end their resistance. A Sunni-Shiite peace agreement could include guarantees of minority rights on the most sensitive political issues, arrangements to eliminate illegal state repression, surrender of the Sunni insurgent organizations, cooperation against foreign terrorists and a timetable for U.S. withdrawal.

If peace diplomacy were to fail after a reasonable period of a few months, the United States could then withdraw on its own timetable in the knowledge that it had made a good faith effort to reverse the slide into war. And equally important, in the process of implementing the responsible exit strategy, the old arguments against withdrawal – that it would lead to sectarian violence, that it would allow a terrorist haven in Iraq, and that it would encourage terrorists worldwide – would have been discredited.

The Bush administration has no incentive to admit that it has been wrong and change is course in Iraq. Leading figures of both parties in Congress, however, could still put U.S. and Iraqi interests ahead of short-term domestic political considerations. In that possibility lies the best hope for peace for the remainder of this administration.