Some Democrats are calling for immediate withdrawal of combat troops. Others, like Rep. John Murtha of Pennsylvania, are advocating for a certification process of troop readiness before we add to the troops on the ground in Iraq. I believe both options are wrong.

We have vital interests in Iraq and the region, and we can’t let the countless mistakes of the Bush administration in the conduct of the war divert us from continuing to project American power and influence in the region to protect those interests.

There is another option, which commands potentially strong bipartisan support in Congress (and reflects the Iraq Study Group recommendations). It would fundamentally redefine our military mission in Iraq to one of training, antiterrorism operations, and deterrence of foreign intervention and wide-scale ethnic cleansing, while supporting internal and regional efforts to reach a political settlement of ethnic conflicts in the country.

All these options would involve a sharp change of course in Iraq, withdrawal of most conventional combat forces and an unmistakable shift of responsibility to Iraqis themselves. But let’s be clear. The “out now” option likely would compromise U.S. security interests, trigger a full-scale civil war, invite foreign intervention, provide an unprecedented propaganda victory for Sunni jihadists and Shi’a theocrats whose savage violence has been aimed at creating exactly this outcome, and abandon those millions of Iraqis whose suffering under Saddam Hussein will be compounded by more chaos, war and tyranny.

A precipitous withdrawal would also drive the Iraqi government further into the arms of the Iranians (Who else is going to offer them arms, supplies and training?), making Shi’a-Sunni reconciliation even harder and increasing Iran’s regional influence. And it could definitely create a dangerous recruitment point and training base for the international jihadists who remain the key global threat to our, and the world’s, security interests. A rapid and complete withdrawal from Iraq isn’t really a “Plan B”; it’s a “Plan Zero” for liquidating the whole Iraq engagement as hopeless.

Here is a “Plan B” I propose:

Shift responsibility for internal security from the U.S.-led coalition to Iraqi authorities, beginning immediately, proceeding steadily according to the ability of Iraqis to actually take charge, and aiming at the withdrawal of U.S. conventional combat forces by (as the Iraq Study Group suggested) the first quarter of 2008.

Refocus the remaining U.S. forces, mainly training personnel, “embeds” and special operations troops, on the more limited but sustainable missions of training Iraqi security and police forces, fighting jihadist terrorists, and preventing genocide.

Keep pressure on the Maliki government or its successor to make the political accommodations to bring moderate Sunnis into the post-Saddam political order.

Launch a robust diplomatic push to build regional and international support for stabilizing Iraq.

The key to this “Plan B” is that once the U.S. mission in Iraq has changed, precise troop levels and withdrawal schedules will largely take care of themselves, without arbitrary numbers or deadlines. It’s worth noting that many of the “deadline for withdrawal” plans circulating in Congress actually assume we will leave significant nonconventional combat forces in or around Iraq for an extended period of time; most have loopholes for changing the withdrawal schedule as necessary. All the focus on deadlines obscures discussion of the need for a smaller, redeployed force with a crucially different but still urgent mission. Those offering plans for withdrawal of “combat troops” need to be much more explicit about the kind of U.S. troops that should remain.

A smaller force in or around Iraq would continue to attack al-Qaida cells and deny them a safe haven in Iraq’s Sunni regions. It would backstop government forces, prevent a Rwanda-scale genocide, and keep neighboring countries from intervening. This counterterrorism force would consist largely of military trainers, special forces, intelligence and logistics. Some experts also have suggested that this force help Iraqi troops guard borders.

Can “Plan B” succeed? There are no guarantees, but I believe that it strikes the right balance between the unknown but potentially enormous risks of complete failure in Iraq and the public’s strong desire to reduce the pain and losses we are already suffering there. We also know that it is an illusion to think that there are any costfree options in Iraq.

“Plan B” not only could protect our national security interests and give Iraqis a decent chance to build order from chaos, but could build a domestic bipartisan consensus among those Americans who have rejected the administration’s strategy yet still are concerned about the broader struggle against jihadist terrorism and the consequences of a complete meltdown in the Middle East.

The American people want honest leadership on Iraq after being fed a steady diet of untruths and incompetence.

Bush’s “Plan A” has failed. It’s time for “Plan B.”

Harold Ford Jr. is the chairman of the Democratic Leadership Council.