Sen. Biden’s idea looks good on paper, but not in reality.

On Monday, a proposal for ending the chaos in Iraq was put forward by Sen. Joseph R. Biden Jr., D-Del. Biden was addressing the fact that a rising tide of sectarian violence has become the biggest threat to Iraq’s future.

As do many U.S. military commanders, Biden argues that the only solution to this downward spiral is political, not military. His proposal: The United States should facilitate the division of Iraq into three largely autonomous regions for its quarreling factions – Kurd, Shiite and Sunni – with a separate federal status for Baghdad.

Biden is one of the best-informed legislators on Iraq and has made six trips there. So his proposal merits serious attention, especially since more experts are likely to endorse it.

Let me say up front that I am dubious about the plan, even though it reflects a process of ethnic and religious separation already well under way in Iraq. But let me lay out the details before I get to my objections.

Biden notes that Iraq’s Kurds already have their own autonomous region in the north. Many Shiites are promoting the idea of a semi-autonomous Shiite region in the south – call it Shiastan. Iraq’s Sunni minority – strongest in the center and west of the country – is vehemently opposed to such decentralization. But Biden thinks Sunnis might be more amenable to a Sunnistan if they were guaranteed a fair share of oil revenue from the north and south.

The senator points out that the new Iraqi constitution already provides for a loose federal system. The “national unity” government – which is still being formed – will have to thrash out the details over the next few months.

Meantime, sectarian killing is on the rise. Hard-core Sunni insurgents, including former Baathists and the terrorist leader Abu Musab al-Zarqawi, have tried to stir up civil war by targeting Shiite shrines and civilians.

As for the new Iraqi army, which President Bush claims will take over security duties from U.S. troops, Iraqis don’t trust it. Because Iraq isn’t united, the army can’t be either. Sunnis fear Shiite and Kurdish army units.

The police and Iraqi commandos are infiltrated by sectarian militias, who are accused of revenge killings of Sunnis. The Iraqi government says 90,000 Shiite and Sunni civilians have already fled from mixed towns or neighborhoods because they feared reprisals.

Indeed, were it not for the continued U.S. troop presence in Iraq alongside Iraqi forces, the Iraqi security forces would probably split up into ethnic components. Read the authoritative new book Insurgency and Counter-Insurgency in Iraq by Ahmed Hashim, a professor at the U.S. Naval War College who served as a U.S. military adviser in the 2005 battle for Tal Afar, if you want to get a clear picture of the ethno-sectarian divisions within the Iraqi army.

So Biden says we should recognize reality, foster a loose federalism, and encourage the reluctant Sunnis to accept it. He proposes “multisectarian and international police protection” for mixed areas, where ethnic cleansing would worsen if the country moved toward territorial separation. Biden wants to draw Iraq’s neighbors into the plan by inviting them to a regional security conference. And he calls for President Bush to draw up a plan to withdraw or redeploy all but a small, residual force by 2008.

It sounds great on paper, and I commend Biden for thinking outside the box. But I do not think America can afford to publicly promote Iraq’s territorial division. Such a split may be where Iraq is headed anyway, but the decision must be left up to Iraqi politicians, who will be debating the subject furiously this summer.

Nor do I think we can afford to set a timetable for withdrawal now. The Bush administration’s gross mistakes facilitated Iraq’s collapse; without a continued U.S. troop presence it will sink into full-scale civil war.

Even if Iraqi leaders agree on federation, the fighting will continue. No international police will be available to patrol mixed areas; U.S. forces will be required to hold Iraqi units in check. And with the United States and Iran at each other’s throats, we are not likely to see a conference of Iraq’s neighbors.

If the Bush administration wants to calm Iraq down, it should contemplate promoting a regional conference. But it should stay in the background as Iraqis argue over a federal system. Help them, yes. Facilitate, yes. But nothing could be worse for the United States than to be viewed in the region as the imperial agent who dismembered Iraq.

Trudy Rubin is a columnist and editorial-board member for The Philadelphia Inquirer. Readers may write to her at: Philadelphia Inquirer, P.O. Box 8263, Philadelphia, Pa. 19101, or by e-mail at