Syria's moderate rebels are collapsing. Western policy, including hope for next year's peace talks, is crumbling with them. This week, the US and Britain suspended non-lethal aid - such as communications equipment and trucks - to rebels in northern Syria, after bases belonging to the largely moderate, Western-backed Free Syrian Army were ransacked and their equipment seized by the Islamic Front.
This rebel-on-rebel fratricidal orgy sums up so much that has gone wrong with Syria's revolution. The Islamic Front, a recently formed coalition of seven of the most powerful rebel groups from across Syria, is dominated by Salafis - Sunni Muslims who hold to puritanical and literalist readings of Islam.
None of its members are US-designated terrorists, and they collectively oppose the most powerful and extreme jihadist group in Syria, the rapidly growing Islamic State of Iraq and al-Sham, which is out-muscling other rebels.
Yet the Front nevertheless works with the al-Qaeda-aligned Jabhat al-Nusra on the battlefield, and welcomes recruits from among the thousands of foreign fighters - including the thousand-plus European Muslims - who have travelled to Syria to fight Assad. Its aim is an Islamic state under sharia, with an ambivalent, probably inferior, status for Syria's large minority communities.
This is not a moderate group. The Islamic Front's members have also withdrawn from the Free Syrian Army's Supreme Military Council, the main conduit for what little Western arms have trickled in. But it is a sign of the moderates' pitiable military and political standing that they felt compelled, through gritted teeth, to welcome the very same Islamists who had overrun their bases and stolen their weapons: "We believe that those brigades [in the Front] are our brothers."
In truth, moderate rebels are being obliterated as a force. Their best units have peeled away and their foreign support is dwindling to nothing. Saudi Arabia, fed up with American hesitation to provide arms or drop bombs, impatient with the Free Syrian Army's weakness, and eager to check Iranian influence at a time when Washington and Tehran are moving closer together, is throwing its weight behind members of the Islamic Front, particularly the Damascus-based Army of Islam.
Riyadh sees these groups as the only way to contain the growing influence of al-Qaeda. It is also gambling that the Front's members won't turn their guns outside the region or give sanctuary to jihadists once Assad falls. Washington and London do not agree; hence the suspension of aid.
This has important implications for the West's entire approach to Syria. Six out of the seven groups in the Islamic Front have explicitly rejected US and Russia-backed peace talks, the so-called Geneva II conference set for January 22, and some have threatened to try for treason those moderate rebels who attend.
It is, therefore, impossible to imagine anything productive coming out of next month's talks, whose main purpose appears to be keeping up appearances of diplomacy. Those who might attend - like the Syrian National Coalition, the political body linked to the moderate rebels - have little ability to influence events on the ground; those with the influence, like the Islamic Front, will not show up (nor is it clear that the Assad regime would talk to them if they did).
The US might threaten the Islamists with a terrorism designation if they don't participate, but it is hard to see this working. As for the regime's sponsors, Russia will attend and Iran would do so if invited. But both Moscow and Tehran assess that military trends are on Assad's side.
Over the past weeks, government forces, helped by Hizbollah fighters from neighbouring Lebanon, have won a string of victories in the Qalamoun region near the Lebanese border. This could tighten the regime's grip over the north-south axis of the country, protect the pro-Assad coastal areas, and choke off rebel links in and out of Lebanon.
Why, then, do we expect either of Syria's allies to apply pressure on Assad to initiate a genuine political transition? They can see that the rise of jihadists, along with the continued imperative of destroying Syria's chemical weapons stockpile by next summer, has pushed Western powers away from regime change.
The US still wants Assad to go, but it wants the Syrian state - which must include parts of the military forces brutalising Syrian towns and cities - to survive. The window has closed on arming moderates, but the US won't arm the Islamic Front.
So Western efforts will now turn to containment: shielding Lebanon, Turkey, Israel, and Iraq from the spill-over, checking the spread of jihadists, tracking European fighters returning to their home countries, destroying Syria's chemical weapons, and praying that next year's peace talks do not degenerate into a complete farce.