The new peace envoy to Syria, Lakhdar Brahimi, is drawing up plans for a 3,000-strong peacekeeping force that could involve European troops in policing a future truce.
Given the volatility of the conflict and the growing presence of Islamists on the rebel side, it is thought British and American forces would be unlikely to take part because of their past involvement in Iraq and Afghanistan.
Instead, Mr Brahimi is thought to be looking at more nations that currently contribute to Unifil, the 15,000 strong mission set up to police Israel’s borders with Lebanon. They alone are thought to have the infrastructure and on-the-ground knowledge that any peacekeeping operation would require.
Countries contributing to Unifil include Ireland, Germany, France, Spain and Italy, one of which would be expected to play a leading role in the Syria peacekeeping force.
Yet the presence of any European on the ground in Syria – even from nations considered more “neutral” in the Arab world – would still represent a significant new Western military involvement in the Middle East. Experts fear they could be a magnet for attacks for both Islamists and regime loyalists.
Details of Mr Brahimi’s plans emerged as he arrived in Istanbul on Saturday for talks aimed at quelling rising tensions between Syria and Turkey.
Last week, following several days of cross-border shelling by the two countries’ armies, Turkey intercepted a Syrian-bound passenger jet after claiming to have received reports it had Russian-made defence equipment on board.
Meanwhile, in a sign of the challenges facing Mr Brahimi’s mission, Syrian human rights groups reported some of the heaviest on-the-ground fighting to date.
The London-based Syrian Observatory for Human Rights said that a rebel offensive that began in the north on Thursday had killed more than 130 soldiers in two days, and that another 250 were taken prisoner. The Syrian government, meanwhile, has been using ever more air power, hammering rebel units on the border with Lebanon.
Despite the escalating ferocity of the fighting, the British government has effectively ruled any direct military intervention in Syria for now, pointing out that unlike in Libya, there is no clear frontline, and that both sides are also backed by regional powers.
“The best way forward is engagement and diplomacy, coupled with pressure applied by sanctions,” Defence Secretary Philip Hammond told The Sunday Telegraph. “Syria isn’t Libya.”
Mr Brahimi, 78, became envoy after the resignation in August of Kofi Annan, the former UN Secretary General, whose initial peace plan earlier this year ended in complete failure. Since taking over, Mr Brahimi has deliberately sought to dampen expectations, warning that it might be “nearly impossible” for him to succeed.
Yet he is due to visit Syria soon to try to persuade Damascus to call a ceasefire, and diplomatic sources say his office has been exploring the peacekeeping option in a “very serious” manner.
Already he is understood to have ruled out the use of African troops, who he believes would not be adequately resourced, and troops from neighbouring Arab states, most of which are seen as supporting the rebels.
“Brahimi has asked for the lists of troop contributing countries, and has already ruled out a number of countries, which essentially leaves European troops,” a source said. “He is looking at all options and not putting all his eggs in the peacekeeping basket, but all information points to him exploring the peacekeeping option in a very serious manner.”
Mr Brahimi is also understood to have much more effort to cultivate opposition groups than Mr Annan did, in the hope of eventually getting them to the negotiating table.
At present, though, that seems a distant prospect. Earlier this year, rebels refused to take part in a ceasefire, saying that they did not trust the President Bashar-al Assad’s regime to honour it. And since then, they become much more equal players on the battlefield, whetting their appetite to push for all-out victory rather than a truce that might elements of the Assad regime intact. Any peacekeeping force would also require a mandate from the UN Security Council, two of whose permanent members, Russian and China, have so far backed President Assad.
On Saturday, the Turkish prime minister, Tayyip Erdogan, accused the council of inaction over Syria, saying it was repeating mistakes that led to massacres in the Balkans conflict in the 1990s.
“How sad that the United Nations is as helpless today as it was 20 years ago, when it watched the massacre of hundreds of thousands of people in the Balkans, Bosnia and Srebrenica,” Mr Erdogan said.
In a swipe at Russian and China, he added “If we wait for one or two of the permanent members … then the future of Syria will be in danger.”
Ankara had been hopeful that it might be able to persuade Russia, which sold Syria $1 billion of arms last year, to soften its opposition to military intervention, including a no-fly zone.
But relations with Moscow have deteriorated after Turkey’s forcing down last week of the passenger jet, which Russia insists was carrying only radar components. Yesterday, the Moscow-based Kommersant newspaper said the components came from KBP, a state-controlled weapons manufacturer that makes radar-operated anti-aircraft artillery.
The Foreign Secretary, William Hague, is expected to discuss Syria with his Russian counterpart, Sergei Lavrov, at a foreign ministers’ dinner in Luxembourg tonight.
Elsewhere on Syria’s battlefronts yesterday, government forces rained mortar fire down on the opposition-held Khalidiya neighbourhood of the city of Homs, while there was also fierce fighting near the city of Deraa, where the rebellion began 19 months ago with peaceful rallies.
Meanwhile, Syria’s state news agency said Damascus was ready to accept a Russian proposal for a Syrian-Turkish joint security committee to try to stop cross-border flare-ups.
Additional reporting by Richard Spencer in Cairo and Tom Parfitt in Moscow