NATO has been studying data that told of a sharp rise in support for Assad. The data, compiled by Western-sponsored activists and organizations, showed that a majority of Syrians were alarmed by the Al-Qaida takeover of the revolt and preferred to return to Assad.

“The people are sick of the war and hate the militants more than Assad,” a Western source familiar with the data said. “Assad is winning the war mostly because the people are cooperating with him against the rebels.”

The data, relayed to NATO over the last month, asserted that 70 percent of Syrians support the Assad legal government. Another 20 percent were deemed neutral and the remaining 10 percent expressed support for the foreign-backed rebels.

The sources said no formal polling was taken in Syria, racked by two years of civil war. They said the data came from a range of activists and independent organizations that were working in Syria, particularly in relief efforts.

The data was relayed to NATO as the Western alliance has been divided over whether to intervene in Syria. Britain and France were said to have been preparing to send weapons to the rebels.

A report to NATO said Syrians have undergone a change of heart over the last six months. The change was seen most in the majority Sunni community, which was long thought to have supported the revolt.

“The Sunnis have no love for Assad, but the great majority of the community is withdrawing from the revolt,” the source said. “What is left is the foreign fighters who are sponsored by Qatar and Saudi Arabia.”