However, Rime Allaf, an associate fellow at the Chatham House think tank, argues against making too much of Syria's sectarian tensions.

The regime "has been using the sectarian line, but the opposition and the rebels have increasingly repeated that they do not view it in those terms," she said. "So it's not the Alawites who are crumbling, it's a regime. ... It means many people within that regime, whatever religious denomination they are, they don't necessarily agree with the way things are happening."

Sectarianism aside, the large number of militia groups that have taken up arms across Syria will present a "significant challenge" to the country's future stability whoever ends up in power, Joshi said.

They range from the pro-government Shabiha militia groups, blamed by opposition activists for many of the more brutal attacks on civilians, to rebel hardline Islamist groups and local networks that have formed to protect their villages.

At the same time, the rebel Free Syrian Army, largely composed of soldiers who defected from the al-Assad regime, is more a loose organization of armed groups than a coherent military body, said Joshi.

He predicts that whatever Syrian government results from the conflict will not be in charge of its whole territory, a problem made worse by the porous nature of the country's borders. If the Syrian National Council ultimately does take charge, it may struggle to contain the worst excesses of the militia groups, he said.

The International Committee of the Red Cross said this month that it considers the conflict a "non-international armed conflict" -- or a civil war -- but some analysts say international forces are in fact involved.

Opposition forces are being "quite well-armed and probably trained by external clandestine forces from the Gulf states and probably from Turkey," Plesch said. Questions should also be asked about some European and North American involvement, he added.

At the same time, Syria's neighbors, which include Turkey, Iraq and Lebanon, all have a stake in how the conflict plays out and exert varying degrees of influence within Syria.

Part of the international community's unease stems from Syria's position as a regional powerhouse. "Syria really is the epicenter of the Arab-Israeli conflict, and the international community's confrontation with Iran," said Plesch.

Another concern to those watching from the wings is Syria's stockpile of chemical weapons.

Syria's foreign ministry said Monday that the country has chemical weapons that it would be willing to use against foreign attackers, although it sought to roll back the message Tuesday.

Its remarks led to strong warnings from U.S. officials, including President Barack Obama, who said such a move would be a "tragic mistake."

Obama administration officials are now holding regular high-level meetings to discuss the ongoing situation in Syria and begin thinking about U.S. priorities in a post-Assad era, a senior U.S. official told CNN Monday. The Obama administration has also stepped up its discussions with Israel, Jordan and Turkey about Syria's chemical weapons arsenal

The al-Assad regime "probably has the largest and most advanced chemical warfare program in the Arab world," according to Michael Eisenstadt, senior fellow and director of the military and security studies program at the Washington Institute for Near East Policy.

But there is good reason to be skeptical that this arsenal would ever be used, Joshi said. Syrian commanders would not want to be held individually responsible with no regime to protect them, he said. Commanders are also well aware that the risk of such weapons getting into the hands of allies such as Hezbollah would likely induce external intervention, particularly from Israel.

For some observers, the international community's increasing focus on Syria's weapons stockpile also conjures unwelcome echoes of the run-up to the Iraq war.

Syrian allies China and Russia, who last week blocked another United Nations Security Council resolution for new sanctions if Syrian government forces don't stop attacks against civilians, are opposed to the kind of foreign intervention seen in Iraq as well as in Libya last year.

Moscow indicated Tuesday that Damascus should refrain from making use of chemical weapons in line with its ratification of Geneva protocols. "Russia's policy is based on the understanding that Syrian authorities will continue to strictly follow their international obligations," the foreign ministry said.

As for al-Assad, if he is forced from power, his personal fate will likely depend on whether he remains in Syria, and in whose hands.