LONDON (Reuters) - As Syrian army defectors begin launching attacks on government forces, Syria's largely peaceful rebellion appears in danger of descending into a sectarian civil war with wider regional consequences.
Forces loyal to President Bashar al-Assad on Tuesday attempted to wrest control of a central town from military forces that had gone over to the opposition, whilst in other towns there were also reports of fighters coming together.
Details were far from clear and diplomats and other sources said defecting units appeared a "hodgepodge" who might struggle to mount a sustained fight against superior forces.
Protesters have occasionally seized weapons to attack security forces, but witnesses say protests have been generally peaceful. The appearance of loosely organized groups of military deserters lends a new dimension to the uprising.
"The strategy of peaceful opposition is clearly losing ground in the face of Assad's brutal counter response and the call to arms is gaining currency as the only way of dislodging the regime," said Julien Barnes-Dacey, Middle East analyst at London-based consultancy Control Risks.
"The key question is whether or not this will spread and result in a more decisive break right across the military."
Most believe that is unlikely. Syria's military has long been divided along sectarian lines and most expect that the units most dedicated to Assad -- made up largely of Alawites who are an offshoot of Shi'ite Islam -- will remain loyal. That could leave neither side with the strength to win and open the door to months or years of war.
The risk, experts say, is that neither side feels they can back down with the opposition fearing they will be hunted down and killed if Assad can reassert control whilst Alawites and other allied groups fear reprisals if he goes.
Whilst some in Syria's somewhat unsupported opposition may have ambitions of repeating the success of their counterparts in Libya in ultimately marching on the capital and taking power, few analysts believe that a plausible imminent outcome.
"The regime will most likely use this to in order to justify and further intensify its bloody crackdown," says Anthony Skinner, Middle East and North Africa director at political risk consultancy Maplecroft. "This increases the risk of Syria sliding into a civil war."
Some worry about a further regionalization of the conflict. In Bahrain, largely Sunni Gulf states backed the monarchy as it crushed unrest from primarily Shi'ite demonstrators demanding equal rights in jobs and public services.
That raised hackles on both sides of the Middle East's sectarian divide that could worsen further if largely Shi'ite Iran ramps up support for its long-time ally Assad and Sunni powers such as Saudi Arabia move closer to backing the opposition.
"This has a lot of worrying regional implications, particularly if it leads to Syria moving toward becoming a failed state," said Stephen Heydemann, a senior vice president and regional specialist at the United States Institute of Peace in Washington. "There's a risk it could exacerbate regional tensions that have already been made worse by Bahrain."
Sectarian fighting in Syria could also raise tensions between assorted other smaller cross-border groupings in neighboring countries including Alawites and Kurds in Turkey and Shi'ites and Sunnis in Lebanon.
For now, analysts say it is still too soon to say whether enough soldiers will defect to form a force that could be a significant military threat to the Damascus government.
"The rate of defections is increasing," says Alan Fraser, Middle East analyst for London-based risk consultancy AKE. "However... it is coming amid a fall in the number of protests throughout the country -- which are slowly losing momentum amid the ongoing crackdown. It will take significantly greater numbers of defectors to significantly threaten the regime."
Nor is it yet clear to what extent the wider, somewhat disparate opposition movement wants to embrace a more violent approach.
The Syrian National Council, a unified opposition formed this month to support the uprising, and the Local Coordination Committees (LCC), the grassroots activist network that has powered the rolling demonstrations across Syria over the past six months, are explicitly against recourse to violence.
"It is not a countrywide trend," said Peter Harling of the International Crisis Group. "In parts of the country people have been preparing themselves... but continue showing restraint. In others, they simply cannot afford weapons."
In the longer run, some analysts say the opposition's best hope is to try to hang on in the hope that ever tightening sanctions take their toll on Assad's rule. Sanctions will likely starve his government of the oil sales that make up some 30 percent of government revenue, whilst much of the wider economy is also now effectively moribund or shut down.
"The Libya option isn't there, particularly because the Europeans and other regional powers aren't willing to play the role they played in Libya," said Jon Alterman, Middle East program director of the Center for Security and International Studies in Washington DC.
"There might be the option of some kind of covert operations support for the opposition but it's hard to see what the point or strategy might be."
Many outside groups working with Syria's protesters have long tried to persuade them that taking up arms is the wrong way of pursuing their struggle, encouraging them instead to pursue non-violent methods such as boycotts and strikes.
"Any violence committed by opposition forces will harm the movement," said Srdja Popovic, a Serbian activist involved in the ousting of Slobodan Milosevic in 2001 and who now works with dissident groups worldwide including the Syrians. "It will also diminish the possibility of achieving unity within the Syrian people and building a realistic alternative." (Additional reporting by Dominic Evans in Beirut; Editing by Samia Nakhoul)