THOUGH YOU wouldn't know it from the partisan rhetoric, there is substantial agreement in Washington on the strategy for Iraq outlined yesterday by President Bush. The president denounced those who would "cut and run" from the country and in turn was lambasted by Democrats for inflexibly staying the course. In fact, many Democrats in Congress agree with the principal elements of Mr. Bush's "strategy for victory," which are to build up a representative Iraqi government and security forces to defend it in the next 12 months while gradually shrinking the numbers and duties of U.S. troops.

Mr. Bush rejected the Democrats' demand for a timetable for withdrawal, saying he would "settle for nothing less than complete victory." But such a timetable already exists, drawn up by the generals who report to Mr. Bush and supported by leading Democrats: It calls for the reduction of American forces from 160,000 to 100,000 during 2006. Such a "phased redeployment of United States forces from Iraq" was endorsed by the Senate two weeks ago by a vote of 79 to 19. Notwithstanding the endorsement by House Minority Leader Nancy Pelosi (D) yesterday of the proposal by Rep. John P. Murtha (D-Pa.) for withdrawal within six months, many senior Democrats oppose an immediate U.S. pullout. Democratic senators such as Joseph R. Biden Jr. (Del.) and Hillary Rodham Clinton (N.Y.) agree with Mr. Bush's description of the dangers of allowing al Qaeda's forces in Iraq to claim a victory or permitting Iraq to collapse into a sectarian civil war.

The agreement flows not from converging views over a war that has polarized the country but from a simple absence of choices. To abandon Iraq while the country's emerging leaders are still trying to hammer together a workable political system would be a disaster for U.S. interests around the world. At the same time, the U.S. military cannot maintain its present force levels in Iraq much longer without unpalatable measures, such as sending units for fourth and fifth tours or mobilizing more of the National Guard. Iraqi leaders themselves recognize that they must win the war with their own forces; they recently signed an agreement endorsing a timetable for American withdrawal.

The real question about Mr. Bush's strategy, which few in Congress dare to ask, is whether the means meet the ends. Every plan the administration has prepared, starting with the original invasion, has been based on overly optimistic assumptions and insufficient resources. Now, once again, the strategy supposes a series of successes in the next 12 months that approach the miraculous: the appearance of tens of thousands of capable Iraqi troops; the brokering of a political accord among Shiites, Sunnis and Kurds; the formation of a workable democratic government; an acceleration of reconstruction; a significant decline of the insurgency; and a 40 percent reduction of U.S. forces. But what if Iraqi leaders refuse to compromise, and instead split the country into several pieces? What if Iraqi forces fail to control the insurgency in the areas where they have taken over?

By clamoring for a more rigid and specific troop withdrawal timetable -- or an immediate pullout -- Democrats merely raise the risk of failure. In that sense, Mr. Bush was right to stress yesterday that withdrawals must "be driven by the conditions on the ground in Iraq and the good judgment of our commanders." Yet Mr. Bush continues to understate the magnitude of the challenge. The hard truth, as the administration's own strategy paper puts it, is that "it is not realistic to expect a fully functioning democracy, able to defeat its enemies and peacefully reconcile generational grievances, to be in place less than three years after Saddam was finally removed from power." It's not realistic to expect it after four years, either -- whether or not there are benchmarks and timetables.