As we head into 2007, the war in Iraq will haunt the Bush administration, the new Congress and us all.

President Bush has been reviewing Iraq options; the time he’s taking indicates the grimness of the choices. Many readers have asked me what I think should be done, so here are my thoughts.

Above all, we must clarify our purpose in Iraq. President Bush says, “Our goal remains a free and democratic Iraq that can govern itself, sustain itself and defend itself and is an ally in the war on terror.” This premise assumes we are dealing with a unified country with a viable government. Both assumptions are false.

In reality, our only plausible goal is to contain the mess we’ve made.

Iraq is convulsed by a brutal civil war between Shiite and Sunni Muslims (with ethnic Kurds mostly on the sidelines). Its central government is weak; Iraqi security forces are also split by religion and sect.

Even as the president plans, sectarian militias are changing Iraq’s makeup. In Baghdad and other cities, hard-line Shiite and Sunni militias are driving out all members of whichever sect is the minority in their respective areas. Even as White House officials discuss the formation of a new, moderate, multisectarian political bloc in Baghdad that would isolate both Shiite and Sunni radicals, Prime Minister Nouri al-Maliki is rejecting the strategy. Despite a recent visit to the White House, Maliki won’t isolate the radical Shiite cleric Muqtada al-Sadr and his Mahdi militia. Nor does the prime minister seem capable of pursuing reconciliation with moderate Sunnis.

So, as civil war continues, what can we do to contain the mess?

The option the president supposedly favors would call for a temporary surge of 15,000 to 20,000 U.S. troops to Baghdad. The goal would be to stabilize Sunni and mixed areas (and hope Maliki would then curb Sadr). The surge would follow classic counterinsurgency strategy: Clear and hold an insurgent area and follow with an infusion of U.S. aid.

The potential consequences of our Iraq debacle are so awful that I would endorse a troop surge if I thought it would work. But I don’t.

There are too few additional U.S. troops available for too little time to crush Sunni insurgents; they would flee to Sunni Anbar province and return to Baghdad once we left. Moreover, the situation in Baghdad is no longer a classic insurgency problem. It has deteriorated into a civil war the Shiite-led government is determined to win. U.S. troops would be caught in the middle.

A surge could wind up strengthening the power of the anti-American Sadr, who is backed by Tehran, while hastening the creation of a radical Sunnistan in Anbar. As the civil strife worsens, Iraq’s neighbors – Shiite Iran and Sunni Saudi Arabia, Egypt and Jordan – would feel compelled to give their Iraqi co-religionists more support.

What to do?

At this point, our primary goal in Iraq should be to try to prevent Iraq’s civil war from dragging in surrounding countries. A wider Sunni-Shiite struggle would guarantee more carnage among Iraqi civilians. It would also threaten oil supplies and send oil prices soaring.

That means we must make a last try at promoting Iraqi reconciliation. Iraqi Shiite leaders don’t yet want our troops to leave (they still fear a Baathist revival). Sunni leaders don’t either (they fear being slaughtered by Shiites). This gives us some leverage. There should be no timeline yet for U.S. withdrawal lest we encourage all-out civil war and the beginnings of a regional free-for-all, but we should let Iraqis know our patience is limited.

We must also try to prevent the complete takeover of Sunni areas of Iraq by religious radicals who could turn them into a refuge for Islamic fanatics. That will require arming and aiding Sunni tribal leaders in Anbar who publicly oppose radical Sunni Islamists. This strategy is risky – those arms may go astray – but there is no better choice.

Finally, the goal of containment requires that we promote a regional conference with all of Iraq’s neighbors which involves consultations with Syria and Iran. The administration opposes such a move, and it offers no panacea. Yet I believe Shiite Iran (and Sunni Saudi Arabia) can be made to see the danger of a proxy war over Iraq’s corpse.

We have very little leverage left to prevent such a grim scenario. But our leverage will shrink further if we fail to recognize facts on the ground.