There was more horror in Syria over the weekend, where scores of bodies, most of them civilians, were discovered in a Damascus suburb. The victims are believed to have died in a weeklong offensive by forces loyal to President Bashar al-Assad, who seems to have no misgivings whatever about a slaughter, including the use of airstrikes and missiles, that has claimed more than 70,000 lives so far during two-and-a-half years of war.

Long after Western governments predicted he would be gone, Mr. Assad is hanging on even as his country unravels, deepening sectarian divisions, expanding the fighting across borders and forcing an estimated one million Syrians to flee to neighboring countries. There are increasing fears about whether the country can hold together, whether the fighting will destabilize its neighbors and whether, when all is said and done, extremist groups with connections to Al Qaeda who have been among the best anti-Assad fighters will emerge on top.

Eager to find ways to speed Mr. Assad’s fall, or at least change his calculations, President Obama is edging, cautiously but appropriately, toward greater support for the rebels. Secretary of State John Kerry said on Sunday that Washington would double aid to the opposition’s military wing by providing an additional $123 million in “nonlethal” assistance like body armor and night-vision goggles. Some $385 million in humanitarian aid had already been committed.

The president has wisely resisted calls to supply American weapons and to intervene directly. He should continue to do so. Nevertheless, in recent months, the C.I.A. has helped Arab governments and Turkey airlift arms and equipment to the rebels and provided training. The agency also vetted rebel groups to ensure that only moderates receive those supplies.