WASHINGTON — The White House insisted Monday that it would not be thrown off its cautious approach to Syria, despite apparent Israeli military strikes near Damascus and new questions about the use of chemical weapons in the civil war there.
The administration cast doubt on an assertion by a U.N. official that the Syrian rebels, not the government of President Bashar Assad, had used the nerve agent sarin. And it backed Israel's right to strike Syrian targets to disrupt shipments of weapons from Iran to the Islamic militant group Hezbollah in Lebanon. Iran and Hezbollah are allies of Syria.
President Barack Obama's aides say there is a deep reluctance to be drawn further into a conflict that has killed more than 70,000 people.
Despite that reluctance, the White House is weighing more robust action, including supplying arms to the rebels — in part because of its conclusion that there was a strong likelihood that the Assad government has used chemical weapons on its citizens. The rationale for that response could be undermined, however, if there was proof that the rebels themselves — some of whom are radical Islamists — had also used such weapons.
The assertion that there is evidence suggesting the rebels have used sarin was made by Carla Del Ponte, a former chief prosecutor for international criminal tribunals that investigated Rwanda and the former Yugoslavia who is now serving on a commission looking into human rights abuses in Syria.
But that commission later issued a statement clarifying that it had not reached a conclusion about which side used the gas, and the White House press secretary, Jay Carney, added the administration's doubts.
"We are highly skeptical of the suggestion that the opposition could have or did use chemical weapons," he said.
As for the two apparent missile attacks by Israel over the weekend, which the White House declined to confirm, Carney said Israel had a legitimate concern about "the transfer of sophisticated weapons to terrorist organizations like Hezbollah, and they have a right to act in their own sovereign interest."
Some lawmakers seized on the strikes, and the lack of Syrian resistance, as evidence that the country's air defenses are not as lethal as some in the administration had claimed.
But current and former U.S. air commanders discounted arguments made by Sen. John McCain, R-Ariz., and others, who have said that enforcing a no-fly zone over Syria would be easier and less risky than the administration has portrayed.