By Patricia Zengerle and Susan Cornwell
WASHINGTON (Reuters) - The Senate Foreign Relations Committee approved a resolution on Wednesday authorizing limited U.S. military intervention in Syria, setting the stage for a contentious debate in the full Senate next week on the use of force.
The committee voted 10-7 in favor of a compromise resolution that sets a 60-day limit on any engagement in Syria, with a possible 30-day extension, and bars the use of U.S. troops on the ground for combat operations.
The compromise is more limited than President Barack Obama's original proposal but would meet his administration's goal of punishing Syrian President Bashar al-Assad's government for what the United States says was the use of chemical weapons on Syrian civilians, killing more than 1,400 people.
The relatively close committee vote reflected the broad divisions on the authorization in Congress, where many lawmakers fear it could lead to a prolonged U.S. military involvement in Syria's civil war and spark an escalation of regional violence.
Five Republicans and two of Obama's fellow Democrats - Chris Murphy and Tom Udall - voted against the resolution. Democrat Ed Markey voted "present," saying in a statement that he is still undecided.
The full Democratic-controlled Senate is expected to vote on the resolution next week. The Republican-controlled House of Representatives also must approve it. Both votes are expected to be close, as scores of lawmakers in both parties have yet to stake out a public position other than to say they are looking for more answers.
Obama and administration officials have urged Congress to act quickly, saying U.S. national security and international credibility is at stake in the decision on whether to use force in Syria in response to the use of chemical weapons.
"If we don't take a stand here today, I guarantee you, we are more likely to face far greater risks to our security and a far greater likelihood of conflict that demands our action in the future," Secretary of State John Kerry told the House Foreign Affairs Committee on Wednesday.
"Assad will read our silence, our unwillingness to act, as a signal that he can use his weapons with impunity," Kerry said.
Protesters held hands splattered with blood-red paint in the air behind Kerry as he spoke at a House hearing that underscored the skepticism among lawmakers in both parties about the authorization.
House members peppered Kerry, Defense Secretary Chuck Hagel and General Martin Dempsey, chairman of the U.S. military's Joint Chiefs of Staff, with questions about the duration, targets, potential response and level of international support for military action in Syria.
"Whether we ultimately support a resolution on the use of force or not, it will depend on how these concerns are addressed in the coming days by the administration," Republican Steve Chabot told the officials.
'LIMITS OF AMERICAN POWER'
In the Senate committee, Murphy said he rejected the resolution because he was concerned a strike could make the situation worse in Syria and he feared the possibility of a prolonged U.S. commitment.
"I oppose it not because I don't gag every time that I look at those photos of young children who have been killed by Assad in his lethal attacks. It's simply because I have deep concerns about the limits of American power," Murphy said.
Senate leaders are unsure if Obama can win the 60 votes needed to overcome possible Republican procedural roadblocks. In the 435-member House, a senior Republican aide predicted most of the 50 or so Republicans backed by the conservative Tea Party movement and a number of Democratic liberals will join forces to vote no, leaving the outcome in doubt.
More closed-door briefings are planned for lawmakers in the House and Senate on Thursday as the administration continues to build the case for the use of military force.
The Senate committee vote came after the panel's leaders - Democratic Chairman Robert Menendez and senior Republican Bob Corker - crafted a compromise to meet concerns that Obama's proposed resolution was too open-ended.
Republican John McCain, a proponent of strong action in Syria, objected to the more narrow compromise. The committee adopted his amendments spelling out the policy goals of degrading Assad's ability to use chemical weapons and increasing the military capability of rebel forces.
"These amendments are vital to ensuring that any U.S. military operations in Syria are part of a broader strategy to change the momentum on the battlefield in Syria," McCain said.
The committee rejected Udall's amendment to prohibit air and naval forces from entering Syrian waters or air space, and an amendment by Republican Rand Paul of Kentucky that would have reaffirmed Congress's role in declaring war.
Polls show strong public opposition to U.S. military involvement in Syria, and the debate in the U.S. Congress is unfolding one week after Britain's Parliament rejected British involvement in any military operation.
In Sweden, Obama issued a blunt challenge to U.S. lawmakers to authorize a military strike on Syria.
"My credibility is not on the line. The international community's credibility is on the line," Obama told a news conference in Stockholm. "And America and Congress's credibility is on the line, because (otherwise) we give lip service to the notion that these international norms are important.
Kerry told House lawmakers that at least 10 countries have pledged to participate in a military intervention in Syria, but did not identify them or specify what roles they would play.
Many members of Congress have said they are worried the resolution could lead to the deployment of U.S. ground troops, or "boots on the ground," in Syria - which administration officials said would not happen.
"It's very clear on the House side there is no support for boots on the ground," House Foreign Affairs Committee Chairman Ed Royce told Kerry at the hearing.
Kerry answered flatly, "There will be no boots on the ground. The president has said it again and again."
Kerry had a sharp exchange with Republican congressman Jeff Duncan, who said the administration has a credibility problem after the 2012 deaths of U.S. diplomats in Benghazi, Libya.
"Mr. Kerry, you have never been one that has advocated for anything other than caution when involving U.S. forces in past conflicts," Duncan said. "The same is true for the president and the vice president. Is the power of the executive branch so intoxicating that you would abandon past caution in favor (of) pulling the trigger on a military response so quickly?"
Kerry, a Vietnam War veteran, responded that "I volunteered to fight for my country, and that wasn't a cautious thing to do when I did it."
"We don't deserve to drag this into yet another Benghazi discussion when the real issue here is whether or not the Congress is going to stand up for international norms with respect to dictators," Kerry added.
(Additional reporting by Rachelle Younglai, Vicki Allen, Susan Heavey, Thomas Ferraro; Writing by John Whitesides; Editing by Karey Van Hall and Will Dunham)