WASHINGTON -- A congressional vote on whether to strike Syria could offer the best insight yet on which wing of the Republican Party -- the party's traditional hawks, or a growing bloc of noninterventionists -- has the advantage in the fierce internal debates over foreign policy that have been taking place throughout the year.
Republican divisions on national security have flared over the use of drones, aid to Egypt, and the surveillance practices of the National Security Agency, and the tensions have played out publicly in battles between Sen. John McCain of Arizona, a former Navy pilot and Vietnam prisoner of war, and Sen. Rand Paul of Kentucky, a libertarian-leaning freshman. Mr. McCain memorably called Mr. Paul and his compatriots "wacko birds," and Mr. Paul suggested that hawks like Mr. McCain were "moss covered."
But those intermittent spats could pale in comparison with the fight over whether to attack Syria, an issue on which Mr. McCain and Mr. Paul -- a former Republican presidential candidate and a possible one in 2016 -- are almost certainly going to be the leading spokesmen for their party's two wings.
Two days after U.S. President Barack Obama shocked Syrians by delaying expected American missile strikes, Syria remains off balance, with the military still bracing, the rebels still hoping to capitalize on the confusion, civilians increasingly fleeing across the borders and everyone uncertain whether the attack has been called off for good.
Businesses were open and shops busy in government-held areas around the country on Monday, residents say, but not all government troops had moved out of the schools and other civilian areas they had moved into ahead of the attacks that were expected Saturday.
The fighting, which was in a noticeable lull on Saturday, appeared to be gearing back up. Antigovernment activists and state news media reported clashes across the country on Monday, while Antonio Guterres, the United Nations high commissioner for refugees, said in an interview in Geneva on Monday that another rush of Syrians across the borders meant that roughly a third of the country's population had now been displaced; he estimated that the number of Syrians seeking refuge in neighboring countries was approaching 2 million, with some 4.5 million being driven from their homes in Syria.
Both the government and the armed opposition have moved to capitalize on Mr. Obama's decision to wait for congressional approval for a strike. The government has portrayed President Bashar Assad as a hero for facing down the Americans, and his supporters have circulated jokes on social media mocking Mr. Obama; one campaign features high-quality videos of Syrians old and young using a vulgar phrase to tell him, essentially, to get lost.
Mr. McCain has long advocated intervention in Syria's civil war. After meeting with Mr. Obama at the White House on Monday, he said that it would be "catastrophic" if Congress did not approve the president's proposal and that such a rejection would result in the United States's credibility being "shredded."
Mr. Paul on Sunday made clear his opposition to Mr. Obama's proposal, taking to Twitter and the talk shows to taunt Secretary of State John Kerry. "John Kerry is, you know, he's famous for saying, you know, how can you ask a man to be the last one to die for a mistake?" Mr. Paul said. "I would ask John Kerry, how can you ask a man to be the first one to die for a mistake?"
A top aide to Mr. Paul said Sunday that the senator would mount a lobbying campaign in the House, where senior leaders like Mike Rogers, R-Mich. and the chairman of the Intelligence Committee, will face off against a new vanguard of members like Justin Amash, R-Mich., who are opposed to what they see as risky foreign entanglements.
But even Republicans who are not active supporters of Mr. Paul recognize that the country and their party are susceptible to a come-home-America message at a moment of war weariness and, among conservatives, profound distrust toward Mr. Obama.
"Americans have become increasingly inured to events thousands of miles away, within a distant and disconnected culture," said a longtime Republican strategist Alex Castellanos, citing a nation "exhausted by crises." "They know our country is already overextended and doubt leaders who tell them there are 'no good options' but demand we choose one anyway."
The result, Mr. Castellanos said, is that "Rand Paul is actually in sync with a crisis-weary America and a fatigued GOP."
Mr. Paul is very much aware that the vote offers just that chance to reorient, at least for now, the Republican center on foreign affairs.
And the debate gives him the chance to re-establish himself as the leading voice of the libertarian-leaning Tea Party movement after months in which Sen. Ted Cruz of Texas has won significant attention.
"Right now, the easy Republican vote looks like the vote against Mr. Obama," said Michael Goldfarb, a neoconservative lobbyist and writer. "Ten days from now, a vote against Mr. Obama could look like a vote for Assad, especially if Republicans succeed in blocking U.S. action, and Assad goes on to prevail, having used chemical weapons, with Iran at his side."
• A breakdown of developments and opinions from around the world in regards to the situation in Syria. Page A-3.