Syrian war

CIA-backed rebels under blitz

For years, the CIA effort had foundered -- so much so that over the summer, some in Congress proposed cutting its budget. Some CIA-supported rebels had been captured; others had defected to extremist groups. The secret CIA program is the only way the U.S. is taking on Assad militarily. In public, the United States has focused its efforts on fighting the Islamic State and urging Assad to leave office voluntarily.

"Probably 60 to 80 percent of the arms that America shoveled in have gone to al-Qaida and its affiliates," said Joshua Landis, a Syria expert at the University of Oklahoma.