BEIRUT (AP) -- With rebels trying to penetrate Syria's capital, Damascus, President Bashar Assad may appear to be heading for a last stand as his weakened regime crumbles around him.
But the Syrian leader is not necessarily on his way out just yet.
He still has thousands of loyal troops and a monopoly on air power. A moribund diplomatic process has given him room to maneuver despite withering international condemnation. And the power of Islamic extremists among the rebels is dashing hopes that the West will help turn the tide of the civil war by sending heavy weapons to the opposition.
"The West, for all its rhetorical bombast, has restricted the flow of important weapons," said University of Oklahoma professor Joshua Landis, who runs an influential blog called Syria Comment. "They have not brought down this regime because they are frightened of the alternative."
There is no appetite for intervening actively against Assad -- as NATO did against Moammar Gadhafi in Libya -- and run the risk of having him replaced by an Islamist regime hostile to the West. Those concerns have deepened after the attack on the U.S. Consulate in Benghazi, Libya, and political turmoil in Egypt where a bid to promote an Islamist agenda threatens to tear the nation apart.
Also working in Syria's favor is its alliance with Russia, which could be losing faith in Assad but will probably not abandon him. Russia has been Syria's key protector at the U.N. Security Council, where Moscow has used its veto power to shield Damascus from world sanctions. On Friday, Russia distanced itself from a statement by its Middle East envoy, who said a day earlier that Assad is losing control and the rebels may win.
During a reign of more than 40 years, the Assad family has built a powerful military and paramilitary force controlled by fellow members of their Alawite sect who are committed to maintaining the once-marginalized religious minority and its allies in power.
While the opposition is making significant gains, the forces propping up the regime are far from spent. For many of them, defeat would mean not only the end of Assad but an existential threat by vengeful rebel forces.
Some observers believe the die-hard loyalists around Assad -- a man who has vowed to live and die in Syria, despite the uprising -- may not allow him to abandon ship, even if he wanted to.
"Assad has effectively held his community hostage and convinced them to go down this road, which could very well lead to horrible retribution," Landis told The Associated Press. "He cannot leave them defenseless by swanning off."
Torbjorn Soltvedt, a senior analyst with the Britain-based Maplecroft risk analysis group, said the close links between the regime and many senior military officers act as a brake on defections in Assad's inner circle. Unlike in Tunisia and Egypt, where the military leadership could envision a prominent role after the removal of the old regime, the fate of many of Syria's senior commanders is linked with that of the Assads, he said.
"A large portion of the Syrian top military elite is unlikely to turn against the regime despite the lack of a successful strategy to regain the initiative in the conflict," Soltvedt said.
So far, air power has been the regime's most potent tool against the rebels, who remain largely helpless in the face of jets and attack helicopters that drop bombs from the sky. The rebels have managed to seize large swaths of territory in the north, overrun military bases and expand their control on the outskirts of the capital.
But rebels admit there is little to do about the threat from above, even though they appear to have shot down a few aircraft in recent months. The airstrikes, which often kill civilians, have in some cases turned residents off the rebellion by making them angry that insurgent fighters are effectively bringing the fight to their doorsteps.
A slow-moving and so-far ineffective diplomatic process also plays directly into Assad's hands. The U.S. has warned the Syrian leader not to cross a "red line" and unleash chemical weapons against the rebels, but beyond that threat there is no clear sign that Washington or its allies want to get involved by sending troops or arming the rebel forces.
That stance may have the unintended consequence of giving Assad broad leeway to continue cracking down in other ways, short of a chemical attack, without any fear of retribution.
The U.S. and NATO this week accused Assad's forces of firing Scud missiles at rebel areas, but the regime has denied that. The government also has been careful not to confirm it even has chemical weapons, while insisting it would never use them against its own people.
Syria is believed to have a formidable arsenal of chemical weapons, including sarin and mustard gas, although the exact dimensions are not known.
While the conflict drags on, there are widening fears that the civil war will ignite neighboring countries, including Lebanon, where pro- and anti-Assad forces have clashed. On Friday, the Pentagon said the U.S. will send two batteries of Patriot missiles and 400 troops to Turkey as part of a NATO force also including Germany and the Netherlands. The force is meant to protect Turkish territory from potential Syrian missile attack.
A number of Syrian shells have landed in Turkish territory since the conflict began in March 2011, and Turkey has been one of Assad's harshest critics.
But NATO's move was not a step toward intervention in Syria. In a statement Friday, NATO spokeswoman Oana Lungescu said "the deployment will be defensive only."
"It will not support a no-fly zone or any offensive operation. Its aim is to deter any threats to Turkey, to defend Turkey's population and territory and to de-escalate the crisis on NATO's south-eastern border," Lungescu said.
Many rebel fighters are bitter that the U.S. and others have not intervened to stop Assad's air force as they did in Libya against Gadhafi.
The fractious nature of the opposition and the increasing power of Islamic extremists among the rebel fighters have been a boon for the regime, as well.
On Wednesday, the U.S., Europe and their allies recognized the newly reorganized opposition leadership, giving it a stamp of credibility though it remains to be seen if the new bloc holds much sway with fighters on the ground.
Those fighters are a growing problem for the West. Some of the rebels' greatest battlefield successes have been carried out by extremist groups with links to al-Qaida. The West, of course, does not want see such organizations wielding any power in the region -- much less running Syria.
Moreover, the opposition appears split over how much to embrace the Islamist fighters.
The president of the new opposition coalition, Mouaz al-Khatib, has disagreed publicly with the U.S. decision to blacklist Jabhat al-Nusra, an al-Qaida-linked force that has proved to be one of the most successful fighting groups in the war against Assad.
Support for al-Nusra appears to be gaining traction among those who support the rebellion -- no doubt alienating many Syrians who hope for a secular future. On Friday, according to amateur video footage posted online, some crowds calling for the downfall of the regime rejected the U.S. designation of al-Nusra as terrorists and carried signs that said: "We are all Jabhat al-Nusra."
The AP could not independently verify the videos, but they appeared to be in line with other reports coming out of the area.
The threat of Islamic extremism resonates deeply in Syria, a country with many ethnic and religious minorities. The Assad dynasty has long tried to promote a secular identity in Syria, largely because it has relied heavily on its own Alawite base in the military and security forces in an overwhelmingly Sunni country. Assad has warned repeatedly that the country's turmoil will throw Syria into chaos, religious extremism and sectarian divisions.
The opposition has so far failed to put forth a credible alternative to Assad, a shortcoming which has kept many Syrians on the fence even as he appears increasingly to be losing control.
"The opposition is not a government," Landis said. "They do not offer social security or retirement payments or a pension. There are millions of Syrians who depend on that government. ... Can this new coalition that America just recognized step in and take their place?"
Still, Landis said, Syrians will likely abandon the regime in increasing numbers -- but "with a fearful heart."
"They've got nobody to look after them," he said. "There are 23 million Syrians who are going to be out of luck, out of food, and out of money."