The battles that continue to rage around Damascus International Airport appear to indicate that Syrian President Bashar Assad's position is becoming more tenuous.

After months of standoff, during which Assad's loyalists succeeded in maintaining control over a substantial portion of the country's territory and strategic assets, the regime has suffered some serious setbacks over the past two weeks. No one in the intelligence community, either in Israel or in the West, is prepared to risk a forecast as to when Assad will actually fall. But it seems there has been a change of momentum in the Syrian civil war.

Rebel groups have succeeded in disrupting activity at the airport - a serious blow to the morale of the regime, which is being forced to divert weapons supply planes sent by Iran to military airfields. The rebels have also taken control of additional military bases in the Damascus region in recent days, and have strengthened their hold on various neighborhoods in the major cities of Damascus and Aleppo.

Israel's defense establishment ascribes the rebels' military successes to the broader aid, both financial and military, that they are now receiving from the West, Turkey, and Arab states like Saudi Arabia and Qatar. Some of the rebel groups have acquired advanced weapons, including anti-aircraft missiles, which have helped them shoot down numerous Syrian air force helicopters and airplanes. Assad loyalists are losing additional aircraft to poor maintenance.

As far as can be determined, coordination among the rebel groups has also improved. The pressure Assad is under is manifesting itself in the tougher measures he is taking against the rebels, including fuel-air bombs, which have been causing enormous environmental damage to towns and neighborhoods under rebel control.

U.S. Defense Secretary Leon Panetta said yesterday in Kuwait that American intelligence services haven't detected any signs that Assad has changed the way he is handling the chemical weapons stores at his disposal. But Panetta reiterated that as the rebels score more successes, Washington fears the regime may unleash chemical weapons against them.

Last week, the United States and other nations warned Assad against this. "I'd like to believe he got the message," Panetta said.

Israeli officials believe that Assad was preparing for the possible use of chemical weapons, "but when the Syrian president heard the international reaction, which included Russian and even Iranian objections, he backed down," an Israeli government source said.

Israel's greatest concern is that chemical weapons (along with other important weapons, like advanced anti-aircraft missiles ) might be transferred from Syria to Hezbollah in Lebanon. But if the Syrian regime uses chemical weapons against the rebels within its borders, it looks as if the Western powers will take action to scuttle the threat. The United States, with the help of France and Britain, has drawn up a detailed plan for dealing with Assad's chemical weapons caches; Israel views this plan as serious and likely to yield reasonable results if implemented.

Within Syria, more than 10 percent of the population, some two million people, have been forced out of their homes or fled them to seek a respite from the fighting. The looming winter threatens to make life in the makeshift refugee camps even harder. Around half a million Syrians have found refuge abroad.

Open gallery view A statue of the late Syrian president Hafez Assad in the rebel-controlled Idlib region. Credit: AFP