Britain and the United States have suspended assistance to Syrian rebels as the opposition continues to fracture and fall under the influence of hard-line Islamists. The hold on supplies of non-military assistance such as body armour, communications equipment and, in the American case, armoured vehicles was in direct response to the takeover by a new pan-Islamist faction of army posts in the north belonging to the Western-backed, secular-led Free Syrian Army and its Supreme Military Council.
Among the buildings seized were warehouses storing Western aid, including vehicles, food and other supplies. There has also been fighting between the al-Qaeda factions that did not join that alliance and both the FSA and yet another, non-Islamist alliance whose launch was announced this week, allegedly with ties to Saudi Arabia.
"We are currently investigating events that took place over the weekend," a Foreign Office spokesman said. "While that investigation is under way, we will not be making any deliveries of equipment to the Supreme Military Council.
"We intend to resume support as soon as we and the SMC are satisfied the conditions on the ground allow the SMC to take safe delivery of equipment provided." The suspension of aid has greater symbolic than real consequences, as neither Britain nor the US provided the lethal military assistance the rebels have so long demanded. Much of the rebels' weaponry comes from defectors and seized government bases.
The rest has been provided in fits and starts by the rebellion's backers in the Gulf, largely Saudi Arabia and private donors who have favoured Islamist-led brigades. The Islamic Front, announced last month, combines a number of brigades including non-al-Qaeda militants who want a hard-line Sharia state.
It rejected both allegiance to the Western-backed political leadership of the Syrian National Council and to peace talks planned for Geneva next month. British and American envoys met some of the Islamist leaders that make up the front in October in the hope of reforging an alliance. Its seizure of FSA headquarters near the Bab al-Hawa crossing with Turkey in Syria's far north-west would seem to suggest that alliance is dead in the water.
In a further blow, two FSA commanders, Mohammed al-Qadi and Ahmad Jahar, were abducted by members of one of the two main al-Qaeda factions, - the Islamic State of Iraq and al-Shams (ISIS) - near the border town of Azaaz. Their bodies were later found nearby.
Perhaps most distressingly of all to those who sympathised with the original goals of the Syrian revolution, one of the country's best-known secular activists, who had been among the first to raise her voice against President Bashar al-Assad, was abducted this week with her husband and two colleagues from a rebel-held town near Damascus. Again, militants are thought to be responsible.
Razan Zeitouneh had been arrested several times by the regime but had condemned a spate of kidnappings by ISIS. Louay al-Mokdad, a spokesman for the FSA, called on the West to reconsider its suspension, saying the decision was "rushed and mistaken". However, the FSA itself has suffered from splits, and a former spokesman, Fahd al-Masri, said the decision demonstrated the failure of Gen Salem Idriss, the FSA leader, who now had virtually no military support on the ground.
He said that the aim of the West appeared to be to ensure the victory of neither the regime nor the opposition, but rather to let both sides bleed. "I am reminded of what Henry Kissinger said about the Iran-Iraq war, when he said the best outcome would be for both sides to lose," he said.
The regime this week secured another tactical victory in its objective of holding on to power in Damascus and Syria's main western corridor when it recaptured the strategically important city of Nabuk. The victory, accompanied according to opposition activists with the deliberate killing of women and children, enabled it to push its attack further, including on the outskirts of Yabroud, an important staging post for rebel supplies near the Lebanese border.
Those supplies are in any case now cut off by heavy snow on the border, which one local resident said had trapped 27,000 refugees in the town. "Yabroud is under siege from the highway," another man, a local aid worker, said. "People are in a horrible situation there. They are trying to escape by whatever way they can."