As western and Arab governments prepare to meet in Marrakech today under the "Friends of Syria" rubric, the US is scrambling to adapt its Syria policy to an increasingly complex reality that is changing rapidly, largely beyond western influence.
Last week's flurry of conflicting reports suggesting President Bashar Al Assad might be preparing to use chemical weapons may have been more a sign of agitation in Washington than of suicidal thoughts in Damascus. The regime has long been aware that using chemical weapons would prompt western powers to unleash air strikes. Israeli analysts have suggested that the greatest danger was not the use of chemical weapons, but that advancing rebels might seize them. Any activity around weapons depots may have been a result of munitions being moved for safekeeping.
Still, it seemed as if someone in Washington was trying to get the urgent attention of policymakers by sounding doomsday alarms. Rebel forces certainly made astonishing gains during the past month - they've overrun key outlying regime military bases; downed regime aircraft with shoulder-fired missiles; moved closer to cutting off the Assad garrison in Aleppo and launched a sustained operation in the suburbs of Damascus.
The regime's strategists may be acknowledging that it can no longer rule all of Syria, and must instead contract its domain, fighting to hold on to key routes and cities, but accepting that recapturing the swathes of territory in the north, east and south held by rebels is beyond the manpower of the regime's reliable (predominantly Alawite) security forces.
If so, the regime's security core may see its best hopes for survival in the "Lebanonisation" of Syria - a scenario, already under way, in which the central state effectively collapses, and power is carved up among local and regional sectarian militias defending their own turf in a long-term war of all against all. The regime has already ceded territory along the Turkish border to Kurdish militias that have no intention of bending the knee to Damascus, regardless of who rules there.
But whereas Syria played the hegemon to contain the effects of Lebanon's civil war, there'd be no neighbour able to limit the fallout from a similar fracturing of Syria itself - already its civil war has spread into Lebanon and Iraq. Hence the mounting anxiety in western capitals - even the former US secretary of state Condoleezza Rice recently warned in The Washington Post that Syria epitomised the breakdown of the nation-state system established in the Levant by Britain and France after the Second World War.
This week opened with news that rebel fighters had overrun the Sheikh Sultan military command centre north of Aleppo. But Washington wouldn't have celebrated; it had, on Monday, designated the rebel group leading the Sheikh Sultan assault as an international terrorist organisation. Jabhat Al Nusra, seen as an offshoot of Al Qaeda in Iraq, fields a relatively small number of cadres, but punches above its weight by being well-armed and funded, salted with battle-hardened veterans of Iraq's insurgency. That makes the Nusra fighters a valuable ally even to more moderate rebel commanders on the ground. Indeed, western-backed Syrian opposition groups had reportedly urged Washington to hold back on the terrorist designation.
US tolerance of allies equipping potentially hostile groups has been eroded by the news that Libyan jihadist groups, such as the one that attacked the US consulate in Benghazi on September 11, had received arms originally provided by Qatar. The New York Times noted that in Syria: "The United States has growing concerns that, just as in Libya, the Qataris are equipping some of the wrong militants."
It remains to be seen how receptive other rebel groups are to a power they have criticised for refusing to provide arms now telling them that their comrades-in-arms are off limits.
Washington and its allies hope to strengthen the moderate Syrian National Coalition, recently formed under their prodding in Doha as the leadership of the rebellion. While European and Arab governments have recognised the coalition as the "sole legitimate representative of the Syrian people", and the US is expected to follow suit, it's not clear that it enjoys the same status on the ground, where the crumbling of the Syrian state has transferred power to a plethora of local militias.
Establishing the credibility of the coalition, its leaders admit, requires making it the sole address for foreign economic and military aid to the rebellion. France and Britain appear to be game, pressing for an easing of the EU arms embargo that prevents them from joining Qatar and other Gulf states in arming the rebels. Hawkish voices in Washington also insist that the only way for the US to acquire influence in Syria is to arm allies among the rebels.
But recent grim experience in Afghanistan (during the 1980s and today) and Iraq demonstrates that arming proxies hardly ensures influence. Moreover, even if the rebels are equipped to force the regime's army into a scorched-earth retreat from Damascus, that won't end the civil war. It could simply confirm the collapse of a state that won't easily be rebuilt.
Good thing, then, that the US continues to seek a political solution in negotiations with Russia, the Assads' most powerful backer. Containing the dangers of Syria's collapse requires cooperation among all the foreign stakeholders whose support for local proxies fuels the civil war. But that would mean widening the diplomatic circle beyond the "Friends of Syria".
Many in Washington view Syria as an opportunity to strike a blow at Tehran. But as UN envoy Lakhdar Brahimi has made clear, if the goal of diplomacy is to create stability in a post-Assad Syria, refusing to engage Iran - the key sponsor of continued regime resistance - is self-defeating.
Tony Karon is an analyst based in New York
On Twitter: @TonyKaron