On Monday, to mark the third anniversary of President Bush’s famous appearance on the USS Lincoln to announce that “major combat operations in Iraq have ended,” Senate Democratic Leader Harry Reid of Nevada issued a press release in which Bush’s text was counterposed with barbed reminders of everything that has gone wrong in Iraq since that boast.

It was a rhetorical low blow, apparently designed to weaken still further the eroding public support for the war, but offering no alternative strategy for ending it.

That same morning, another senator, Joe Biden of Delaware, set forth a much more useful and responsible approach – in a speech to the World Affairs Council in Philadelphia, a New York Times op-ed written with Council on Foreign Relations President Emeritus Leslie Gelb, and a long phone interview with me as he drove from Philadelphia to Washington.

Biden, the senior Democrat on the Foreign Relations Committee, is a supporter of the war who – like John McCain – has been a consistent critic of the administration’s military strategy and diplomacy.

This week, after his sixth trip to the war zone, he said that the threat of sectarian violence – an incipient civil war between Shiites and Sunnis – has become so great that the United States must redefine its political goals in Iraq. Instead of betting everything on the creation of a unified government in Baghdad, Biden said, we should encourage the development of separate but linked regional authorities in northern Iraq for the Kurds, in southern Iraq for the Shiites and in central Iraq for the Sunnis.

The current constitution gives the 18 provinces of Iraq the right to form regional groups. Biden would retain control of defense, foreign policy and oil resources for the central government now on the way to formation, but let the regional governments largely run their own affairs.

This is, he told me, not a call for partition. It is a recognition of what he considers a reality – that the component parts of Iraqi society need “breathing space” to adjust their relations, rather than continue down the present road where militias loyal to one side or the other are engaged in wanton killing and a virulent form of ethnic cleansing.

It is this violence that poses the main threat to Iraq’s security now and that makes it impossible for the American forces to set a departure date.

Biden’s view is that Sunnis will continue to support the insurgency rather than accept a unified government in which Shiites dominate and in which oil revenues are monopolized by the Kurds in the north and the Shiites in the south. Give them a territory of their own, in the center, and guarantee them a share – say 20 percent – of the national oil revenues, and they will consider themselves well rewarded.

The Shiites in turn would know that they would continue their leading role in the national government, but would not face a virulent insurgency supported by the Sunni population.

And the Kurds, who clearly want as much autonomy for themselves as they can get, would be willing to grant a similar degree of self-government to the Sunnis and the Shiites.

Under those circumstances, Biden argues, the rival militias would stay home – or safely disband. And under those conditions, the U.S. could realistically announce its intention to withdraw the bulk of its military by 2008, leaving only a residual “over-the-horizon” force to see that the political agreement is kept.

There are other parts of the plan – a regional summit and a “contact group” of neighboring countries to see that the pledges are honored, and a resumption of American economic aid, conditioned on respect for women’s and minority rights.

There are also risks, which Biden acknowledges, in such an approach. The central government might be too weak to fend off external threats. Regional autonomy could lead to permanent division of the country.

But he offers two analogies that recommend this gamble: One is the Articles of Confederation, which served as a way station for the 13 original states to the stronger government that was embodied in the Constitution. And it is similar to the Dayton accords that ended the warfare in the Balkans and created two separate entities, which now are coming together in a unified Bosnia.

At a time when most people see nothing but hopeless discord in Iraq, it is healthy to have someone offering alternatives that could produce progress.