WASHINGTON — President Barack Obama's cautious response to Syria's likely use of chemical weapons reflects a lack of agreement in Washington over aggressive military intervention, but lawmakers in both parties fear that inaction could embolden not only Syrian President Bashar Assad but U.S. foes as well.
The White House cautiously acknowledged that the Syrian government has used chemical weapons, most likely the agent sarin, in the two-year civil war that has killed more than 70,000 people and displaced hundreds of thousands more.
Obama has declared that the Assad regime's use of chemical weapons would cross a "red line" for a major military response, but the White House made clear Friday that even a quick strike wasn't imminent.
White House spokesman Jay Carney said the prospect of the use of chemical weapons in Syria is "gravely serious," but he insisted the administration needed more evidence to bolster its intelligence assessments.
"This is not an airtight case," he said. "We do have some evidence, but we need to build on that."
Emerging from a closed-door briefing with Secretary of State John Kerry on Capitol Hill, House Republicans and Democrats expressed uncertainty about the appropriate next step as the Obama administration considers limited military options.
No lawmaker pressed for a U.S. military invasion after more than 10 years of war in Iraq and Afghanistan.
"It is such a muddled picture," said Rep. Hal Rogers, R-Ky., chairman of the House Appropriations Committee. "I think probably we should be asking the U.N. to be involved. I think perhaps that's in the making."
Rep. Dutch Ruppersberger of Maryland, the senior Democrat on the House intelligence committee, was among many lawmakers who called for a cautious approach to Syria even as they acknowledged the seriousness of the situation.
"We want to do everything we can to avoid putting boots on the ground," he told reporters. The U.S. should work with other countries to stabilize Syria and ensure its chemical weapons are kept out of the hands of terrorist groups, he said.
"I don't think that we, just as the United States, want to go in to another war," Ruppersberger said.
Obama's vow that Syria's use of chemical weapons would elicit a strong response and the administration's latest caution raise questions about Obama's definition of a red line. The U.S. credibility and international authority are on the line in the administration's handling of Syria, and the message it sends to Assad and rogue nations such as North Korea and Iran.
"There's no question that when the United States takes a position that this crosses a line that our failure to respond has implications," said Rep. David Cicilline, D-R.I., a member of the House Foreign Affairs Committee. "I think the president was saying the use of chemical weapons is a game changer. I think most people agree with that. So that if we in fact determine that chemical weapons were used, I think the expectation is that we and the coalition and others take some action."
Rep. John Mica, R-Fla., wondered whether the red line is "turning into a pink line."
"It's in their ballpark now," he said.
The White House faces a limited choice of military options to help the rebels oust Assad.
Arming the rebels runs smack into the reality that a military group fighting alongside them has pledged allegiance to al-Qaida. Establishing a no-fly zone poses a significant challenge, as Syria possesses an air defense system far more robust than what the U.S. and its allies overwhelmed in Libya two years ago.
The next move on Syria was high on the agenda for Obama's meeting Friday with King Abdullah II of Jordan, as the U.S. ally has struggled with the influx of hundreds of thousands of refugees escaping the Syrian violence. Vice President Joe Biden and Abdullah discussed the best path to "a peaceful, democratic post-Assad Syria where moderates are empowered" on Thursday.
"I think it's important for the administration to look for ways to up the military pressure on Assad," said Sen. Carl Levin, D-Mich., chairman of the Armed Services Committee.
One of the most powerful of the rebel groups in Syria is Jabhat al-Nusra, which recently declared its affiliation with al-Qaida. Last December, the State Department designated the group a terrorist organization, and the administration's opposition to directly arming the Syrian opposition stems from concerns about the weapons ending up in the hands of Islamic extremists.
Arming the rebels, said Sen. Lindsey Graham, R-S.C., is a "lot harder that it was before."
"We've gotten to the point now where the opposition has been affected by the radicals," Graham said in an interview. "Right weapons in right hands is the goal. The second war is coming. I think we can arm the right people with the right weapons. There's a risk there, but the risk of letting this go and chemical weapons falling into radical Islamists' hands is the greatest risk."
Several lawmakers, including Sen. John McCain, R-Ariz., have called for the U.S. to create a narrow, safe zone inside Syria, along its border with Turkey.
Either a safe zone or a no-fly zone would require neutralizing Syria's air defenses. According to a report by the Institute for the Study of War, Syria's largely Soviet-era air defense system includes as many as 300 mobile surface-to-air missile systems and defense systems, and more than 600 static missile launchers and sites.
"You can establish it (safe zone) by taking out their aircraft on the ground with cruise missiles and using the Patriot (missile) also. No American manned aircraft in danger," McCain said.
The U.S. has taken only minimal military steps so far, limiting U.S. assistance to nonlethal aid, including military-style equipment such as body armor and night vision goggles.
The U.S. has deployed about 200 troops to Jordan to assist that country's military, and participated in NATO's placement of Patriot missile batteries in Turkey near the border to protect against an attack from Syria.
In testimony to Congress last week, Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, was asked whether he was confident that U.S. forces could secure the chemical weapons caches within Syria.
"Not as I sit here today, simply because they've been moving it and the number of sites is quite numerous," Dempsey said.
Associated Press Intelligence Writer Kimberly Dozier and AP writer Richard Lardner contributed to this report.