Whatever label the world gives it, Syria's worsening conflict justifies a UN warning of imminent civil war following massacres that have heightened the risk of widespread sectarian violence.

Political analysts say several powerful factors are setting the stage for prolonged turmoil: the increasing brutality of the state and its proxies, better organised and armed rebel forces, devastating suicide attacks by shadowy armed groups, and growing interest by neighbouring countries in arming various parties to the violence.

Whether that translates into a conventional military conflict between combatants controlling rival territorial fiefdoms, or some form of intensified insurgency, is not clear.

But UN Secretary-General Ban Ki-moon's warning, given to reporters after a closed session of the Security Council on Thursday, was a justifiable gambit to alert outside powers that worse lies in store if peace moves remain stillborn, they say.

'To me today Syria smells and feels like Lebanon in 1975,' said Lebanese-born academic Fawaz Gerges, referring to the year Syria's small neighbour descended into a 15-year civil war fuelled by sectarian tensions and regional power struggles.

'Massacres pour gasoline on a raging sectarian fire, and if they continue, Syria will most likely descend into sectarian strife,' said Gerges, Professor of Middle Eastern Politics at the London School of Economics, referring to growing tensions between the Awalite minority of President Bashar al-Assad and the country's Sunni Muslim majority.

'Once bridges of trust break down, once huge quantities of blood are spilled in massacres, communities turn against one another overnight. That is exactly how the civil war started in Lebanon.'

The Syrian opposition and Western and Gulf nations seeking Assad's overthrow increasingly see a peace plan put together by UN envoy Kofi Annan as doomed because of Syria's consistent use of military force to crush an increasingly militarized opposition.

'The danger of a civil war is imminent and real,' Ban said, adding that 'terrorists are exploiting the chaos.'

Ed Butler, the executive chairman of security consultancy Salamanca Risk Management and a former British special forces brigadier, told Reuters he saw multiple internal and external factors which would lead to a full-blown civil war in Syria.

'The three main internal factors would be the consent of the people, the capability of the rebel forces and the capability of the Syrian Army. The recent atrocities have undoubtedly led to an increase in the number of consenting voices amongst the Syrian people, but we question the capability of the rebel groups.'

Rebel forces had proven well organised at local level, he said, but appeared to lack the logistical ability to merge into a cohesive, durable national force which would challenge the army, which was far better equipped than Muammar Gaddafi's Libyan forces in February 2011.

Others see some opposition groups as increasingly able.
 
Paul Rogers, Professor of Peace Studies at Britain's Bradford University, said he suspected Ban's assessment reflected an appreciation of the growing militarisation of the conflict and also a reduction in the government's ability to control all of its territory.

'Really what Ban is saying is that Syria is moving along a path from a rebellion to an insurgency to a civil war, and part of that is because of the territorial element, when the central government no longer controls all the land.'

'In many wars the acquisition of control of terrain by emerging armed groups tends to lead to a more embedded conflict. And in Syria elements of the opposition are now quite well organised and supplied and inflicting quite serious casualties on the government, even if the opposition as a whole remains fractured.'

The terminology used by the international community to describe conflict is not purely theoretical, because it may affect the applicability of international humanitarian law and the prospects for war crimes prosecutions.

On May 8, the head of the International Committee of the Red Cross (ICRC), Jakob Kellenberger, said fighting had been so intense in parts of Syria that at times it had qualified as a localised civil war.

He said conflict in Homs and the province of Idlib this year met the agency's three criteria of a non-international armed conflict - intensity, duration and the level of organisation of rebels fighting government forces.

The ICRC assessment means that international humanitarian law, embodied in the Geneva Conventions laying down the rules of war, is applicable to both sides in some parts of Syria.

It requires the humane treatment of all people in enemy hands and the duty to care for the wounded and sick. But it also means that the parties to the internal conflict are entitled to attack military targets, under international humanitarian law.

Asked if the Syrian conflict had become a civil war, a Western military officer who advised the government of a major Western power during the Bosnian war said he saw Ban's comment as more diplomatic than legalistic in intention: It was an eye-catching way of warning the world that 'things are going to get far worse' without more effective pressure on the combatants.

'There is no sign of either side being prepared to give up, and certainly no sign that the government understands the seriousness of the situation the country is in,' he said.

Rogers said there was now in Syria a dispersed but active opposition cohort of jihadist paramilitaries, who had gained their experience against highly trained and well-armed professional U.S. soldiers and Marines in mid-2000s Iraq.

'It is a singularly dangerous, if hardly recognised, consequence of the war in Iraq, and is likely to prove a severe complication in any attempt to seek an end to the conflict,' he added.-Reuters