Syria's bloody civil war took a dramatic turn over the weekend, with the government blaming Israel for strikes on military targets near the capital, Damascus. And questions about the use of chemical weapons became even murkier after a United Nations official suggested that the Syrian rebels, not the government, had used sarin gas. Here are some questions and answers on the debate over how the United States should respond.
Q. What is the main argument of advocates for greater American involvement in Syria?
A. Supporters of intervention argue that the United States and its allies have an obligation both to buttress the fortunes of the rebels and to protect innocent civilians from the escalating bloodshed. Since fighting erupted in March 2011, more than 70,000 Syrian civilians are estimated to have died in the conflict. Two Republican senators, John McCain of Arizona and Lindsey Graham of South Carolina, advocate providing the rebels with lethal weaponry, enforcing no-fly zones to create humanitarian corridors for refugees, and carrying out offshore airstrikes to degrade Syria's air force.
Q. Why has President Obama been reluctant so far?
A. Mr. Obama, who opened his 2008 bid for the White House with his opposition to what he called a "dumb war" in Iraq, is deeply skeptical that American military involvement will resolve a Syrian civil war that has grown increasingly sectarian. Though he is more open to arming the rebels than he was before reports that President Bashar al-Assad used chemical weapons, he continues to doubt that this would alter the equation on the ground. The president is also wary of arming rebel groups, given that an increasing number of them are tied to radical Islamist groups, including Al Qaeda. And aside from hawks like Mr. McCain, there is little appetite for another Middle East war, either on Capitol Hill or among the public.
Q. How will Israel's recent airstrikes on Syria influence Mr. Obama?
A. It is not clear. The Israelis were responding to a different threat, in the form of weapons being sent to the Islamic militant group Hezbollah. But the Israeli attacks also sent Mr. Assad a strong message of deterrence about using his chemical weapons, which Israelis say pose a particular threat to them. The success of Israeli jets in striking Syrian targets could undermine a major argument of those opposed to American military action: that Syria's air defenses are so robust that it would be very difficult to mount an air campaign like that in Libya.
Q. Will Israel's airstrikes transform Syria's civil war into a regional conflagration?
A. Syria has threatened Israel with unspecified retaliation for the attacks, though Israeli and American officials doubt that Mr. Assad, consumed with his own battle for survival, will do more than issue public condemnations. Still, the strikes underscore that the Syrian conflict is already international: Israel's military was targeting weapons from Iran that were being funneled through Syria to Hezbollah.
Q. What is the status of the investigations of chemical weapons in Syria, particularly given the recent allegations that the rebels may have used the nerve agent sarin?
A. That possibility was raised by Carla Del Ponte, a former war crimes prosecutor who is a member of a United Nations panel investigating the use of chemical weapons in Syria. But after an interview of Ms. Del Ponte was broadcast on Sunday evening, the panel issued a statement saying it had reached no conclusion that the rebels had used sarin. The Syrian regime has leveled this charge before, as have the Russians, but American officials said they did not believe that the rebels had access to chemical warfare agents.
This article originally appeared in The New York Times.