The vote on the nonbinding measure was 12-9 and largely along party lines.

"We better be damn sure we know what we're doing, all of us, before we put 22,000 more Americans into that grinder," said Sen. Chuck Hagel of Nebraska, the sole Republican to join 11 Democrats in support of the measure.

Sen. Joseph Biden, D-Delaware, the panel's chairman, said the legislation is "not an attempt to embarrass the president. ... It's an attempt to save the president from making a significant mistake with regard to our policy in Iraq."

The full Senate is scheduled to begin debate on the measure next week, and Biden has said he is willing to negotiate changes in hopes of attracting support from more Republicans.

House Democrats intend to hold a vote shortly after the Senate acts.

Even Republicans opposed to the legislation expressed unease with the revised policy involving a war that has lasted nearly four years, claimed the lives of more than 3,000 U.S. troops and helped Democrats win control of Congress in last fall's elections.

"I am not confident that President Bush's plan will succeed," said Sen. Richard Lugar of Indiana, senior Republican on the committee.

But he said in advance he would vote against the measure. "It is unclear to me how passing a nonbinding resolution that the president has already said he will ignore will contribute to any improvement or modification of our Iraq policy."

"The president is deeply invested in this plan, and the deployments ... have already begun," Lugar added.

He suggested a more forceful role for Congress, and said lawmakers must ensure the administration is "planning for contingencies, including the failure of the Iraqi government to reach compromises and the persistence of violence despite U.S. and Iraqi government efforts."

Hagel: 'This is a pingpong game with American lives'

Divisions over the war were on clear display as the committee met.

Sen. Chris Dodd, D-Connecticut, said he wanted to change the measure to say flatly that the number of troops in Iraq "may not exceed the levels" in place before Bush announced his new policy. The suggestion failed, 15-6.

Sen. Norm Coleman, R-Minnesota, sought to amend the legislation to show support for an increase troops in the Anbar province in western Iraq, but not in Baghdad, where the sectarian violence is particularly fierce. His proposal also fell, 17-4.

Sen. Russell Feingold, D-Wisconsin, chastised fellow lawmakers, accusing them of being reticent to respond to Bush's plans. He said he would seek passage of legislation at a later date cutting off funds for the war.

Hagel's remarks were among the most impassioned of the day, and he was unstinting in his criticism of the White House.

"There is no strategy," he said of the Bush administration's war management. "This is a pingpong game with American lives. These young men and women that we put in Anbar province, in Iraq, in Baghdad are not beans; they're real lives. And we better be damn sure we know what we're doing, all of us, before we put 22,000 more Americans into that grinder."

A Vietnam veteran, he fairly lectured fellow senators not to duck a painful debate about a war that has grown increasingly unpopular as it has gone on. "No president of the United States can sustain a foreign policy or a war policy without the sustained support of the American people," Hagel said.

At least eight other Republican senators say they now back legislative proposals registering objections to Bush's decision to boost U.S. military strength in Iraq by 21,500 troops.

Democrats push for full Senate vote next week

The growing list -- which includes Sens. Gordon Smith, George Voinovich and Sam Brownback -- has emboldened Democrats, who are pushing for a vote in the full Senate by next week to rebuke the president's Iraq policy.

In his State of the Union speech Tuesday night, Bush urged skeptical members of Congress to give the plan a chance to work.

Many lawmakers remained reluctant.

"I wonder whether the clock has already run out," said Sen. Susan Collins, R-Maine. She said she was worried that U.S. troops in Iraq are already perceived "not as liberators but as occupiers."

Bush did get a word of support from former New York Mayor Rudy Giuliani, one of the 2008 Republican presidential hopefuls.

"I believe we should give the president the support to do this. I want us to be successful in Iraq," he said Wednesday on NBC's "Today" show. "I know how important it is to the overall war on terror. Success in Iraq means a more peaceful world for America, it means a victory against terrorists. Failure in Iraq means a big defeat against terrorists and the war on terror is going to be tougher for us."