WASHINGTON — The Obama administration decided to suspend the delivery of nonlethal aid to Syria’s moderate opposition Wednesday, a move that demonstrated again the frustrations of trying to cultivate a viable alternative to President Bashar Assad just a month before a peace conference that will seek an end to the grinding civil war in Syria.
The administration acted after several warehouses of US-supplied equipment were seized Friday by the Islamic Front, a coalition of Islamist fighters who have broken with the moderate, US-backed opposition, but who also battle Al Qaeda.
Administration officials said that the suspension was temporary and that aid could flow again. Under the administration’s division of labor, the State Department is in charge of supplying nonlethal aid to Syria while the Central Intelligence Agency runs a covert program to arm and train Syrian rebels.
But with rebels feuding with one another instead of concentrating on fighting Assad, and with the United States still groping for a reliable partner in Syria, the odds of any peace conference breaking the cycle of bloodshed appeared to have dimmed.
For the White House, which has pinned its hopes for Syria on a political solution, the fracturing of the opposition raises a number of thorny questions, including whether the United States should work more closely with Islamist forces as it sometimes did in Iraq.
Some experts on Syria said the episode called into question not only the effectiveness of the moderate groups the United States has been supporting in Syria for the past two years but also the administration’s broader strategy for forcing Assad to yield power.
“For all practical purposes, the moderate armed opposition that the administration really wanted to support — albeit in a hesitant and halfhearted way — is now on the sidelines,” said Frederic C. Hof, who as a State Department official who worked on plans for a political transition in Syria and is now a senior fellow at the Atlantic Council.
Under such circumstances, Hof said, the prospects for major progress at the peace conference were “pretty grim.”
In the murky events of last Friday, some opposition officials said, the Islamic Front also seized the northern Syrian headquarters of General Salim Idris, the leader of the military wing of the moderate Syrian opposition, formally known as the Supreme Military Council. According to US officials, Idris was in Turkey, where he has a house, when the headquarters was taken over and then left for Qatar. He is now said to be back in Turkey.
US officials are still struggling to assess what the internecine battle means. “If we’re able to understand that, we could revert to the provision of nonlethal assistance,” a senior administration official said.
The United States, the official said, would not rule out talks with the Islamic Front but said it was too soon to determine whether the administration would abandon its insistence that all US and allied assistance be funneled through the Supreme Military Council.
For months, Secretary of State John F. Kerry has argued that a political solution is the only answer for a civil war that has already led to the death of more than 100,000 Syrians. His goal is to encourage a handover of power from Assad to a transitional government.
But Assad, who has received substantial military support from Iran and Russia, seems as entrenched as ever.
At the same time, the opposition groups that the Obama administration has designated as the legitimate representatives of the Syrian people appear to have grown weaker, in part because of their tenuous ties to many of the rebel fighters inside the country and because of the lukewarm support from the West.
The Syria peace conference is now scheduled for Jan. 22.
A major aim of the meeting is to begin the process of identifying Syrians who might serve in a transitional governing body that would run the country if Assad yielded power.
But as the Islamic fighters have begun to play an increasingly important role in the fight against Assad, the administration is faced with the choice of whether to include their representatives in any transitional government.