TWO WEEKS ago, Congress made clear its opposition to President Bush's plan to send more US troops to Iraq.
Opposing the surge is only a first step. There needs to be a radical change in course in Iraq. The pressure is building on Congress -- especially Republicans -- to act if the president will not.
The best next step is to revisit the authorization Congress granted Bush in 2002 to use force in Iraq.
We gave the president that power to destroy Iraq's weapons of mass destruction and, if necessary, to depose Saddam Hussein. The weapons of mass destruction were not there. Saddam Hussein is no longer there. The 2002 authorization is no longer relevant to the situation in Iraq.
Together with Senator Carl Levin, chairman of the Senate Armed Services Committee, I will offer legislation to repeal that authorization and replace it with a much narrower and achievable mission for our troops in Iraq.
Congress should make clear what the mission of our troops is: to deny terrorists a safe haven, train Iraqis, and help Iraq defend its borders. We should set as a goal removing from Iraq all US combat forces not necessary for this limited mission by early 2008, as the bipartisan Iraq Study Group recommends.
Congress also should make clear that the troops should not stay in Iraq indefinitely and get mired in a civil war.
Repealing and replacing the 2002 authorization is not micromanagement from Washington, it is matching our soldiers' mission to the changing realities in Iraq.
Revisiting the 2002 authorization is the right next step but it cannot be the last step. The United States must also answer a two-word test: "What next?"
Everyone wants to get the troops out of Iraq as soon and as safely as possible. There is great political reward in saying, "I can get us out the fastest."
But while leaving Iraq is necessary, it is not a plan. There needs to be a plan for what we leave behind so that we do not trade a dictator for chaos that engulfs Iraq and spreads throughout the Middle East.
Nine months ago, Leslie Gelb of the Council on Foreign Relations and I proposed a plan, which offers a roadmap to a political settlement in Iraq that gives its warring factions a way to share power peacefully and us a chance to leave with our interests intact.
The plan would decentralize Iraq and give Kurds, Shi'ites, and Sunnis control over their daily lives; bring the Sunnis in by guaranteeing them a fair share of the oil; enlist the support of Iraq's neighbors and the world's major powers to promote the plan with the Iraqis; and withdraw US combat forces by 2008. You can read the details at www.planforiraq.com .
The Bush administration has bet everything on a future that will not happen: Iraqis rallying behind a strong central government that protects the rights of all citizens equally.
Since the onset of sectarian war, there is no trust within the central government, no trust of the government by the people and no capacity by the government to deliver services and security. There is no evidence that we can build that trust and capacity any time soon.
There are two other ways to govern Iraq from the center: A foreign occupation that the United States cannot sustain or the return of a strongman, who is not on the horizon.
That leaves federalism -- an idea a majority of Iraqis have already endorsed in their constitution.
Our plan offers a way to make federalism work for all Iraqis. And it offers the possibility -- not the guarantee -- of producing a soft landing in Iraq. That would be the best possible outcome for Iraq and for America.
Joseph R. Biden Jr. is chairman of the Senate Foreign Relations Committee.