I do not rule out this diplomatic effort to cope with the Syria rebellion by Britain and Russia:
Russia and Britain agreed on Friday to work towards a transitional government in Syria, despite acknowledging differences in their approach to the Middle Eastern country's civil war. ...
"We have a common interest in the quickest end to the violence and the initiation of a peace process, and the preservation of Syria as a territorially whole sovereign state," Putin said after the talks.
Assad has been a death-producing ruler even as he has kept his chemical weapons under control, kept jihadis tamed and used for his state interests, and provided relative stability in his corner of the Middle East. So it would be good to get rid of him.
But if the price of getting rid of him is the proliferation of WMD and jihad sanctuaries in the chaos; and ripples that destabilize Iraq, Jordan, and Lebanon, then perhaps the immediate fall of Assad isn't in our interest.
Yet, Assad in charge of Syria isn't going to be acceptable to the rebels and shouldn't be acceptable to us. But there might be a way to resolve this dilemma under these considerations of preventing chaos-driven problems--devolve power to regions with Syria only a nominally unified state:
We'd need to give the Alawites and their Christian allies a province they demographically dominate on the coast and mountains of western Syria; the Kurds would get a province in the northeast; and the Sunni Arabs would get the rest.
Damascus would be a federal enclave.
Power would be devolved to the provinces, including foreign affairs excepting some symbolic aspects reserved to the mostly nominal federal government. Assad could become president of the Alawite province and carry on as he has.
The Kurds and Sunni Arabs would get their own provinces. Perhaps the Sunni Arabs get multiple provinces based on existing provinces or groupings of them. The various rebel factions could be bought off with control of these provinces.
At the federal level, the rebels would dominate, with a rebel in the position of prime minister representing legal "Syria" at the UN. Powers might be restricted to the federal zone and certain legislative areas not reserved to the provinces, such as allocating oil revenue and tariff revenue to the various provinces.
So we and the rebels get rid of Assad as the ruler of a relatively strong Syria (he will be demoted to just another despot who can't do too much harm to us with his resources); the rebels eject Assad from the presidency of Syria and take charge of the national government as the dominant groups, and control their own people's lives in the provinces; WMD assets outside of the Alawite area are secured (I assume Assad will want to quietly keep some), perhaps with an international force to do the job; Lebanon gets to edge away from resuming the civil war; Israel gets a weakened threat to their north (although the Golan border could get hotter with terror threats, the conventional threat will be much lower for a long time); Turkey and Jordan get to send the refugees back to Syria; Iran and Russia retain a pocket of influence in a rump Assad realm to retain access to Hezbollah or naval and intelligence bases, respectively; the Kurds get the hope of an independent state in fact if not legally; tens of thousands of further deaths might be prevented; and the UN gets to feel that it achieved something through diplomacy.
I'd like to change one thing, however. While this might prevent chaos, I no longer think of this as more than an interim step on the road to defeating Assad completely.
Remember that if by saving Assad we prevent chaos that would causes lots of bad things, Assad was a bad actor even when he restrained those very bad things. So we'd simply have an Assad capable of doing many of those past actions that hurt us and killed people. He'd be weaker, which would be an improvement. But he'd be burning for revenge. Which means he certainly wouldn't consider any deal that allows him to survive to be a true peace deal.
So as we use the deal to secure WMD and hunt down al Qaeda, we should prepare to destabilize Assad in his Alawite province. We should work to depose the Baath regime there to turn the Alawite region into a friendlier kingdom. If we don't, Assad will use his position on the coast next to Lebanon to continue to destabilize Lebanon and pose a threat to Israel by supporting Hezbollah. Assad might even try to bite off chunks of Lebanon to unofficially add to his realm.
Honestly, I couldn't care less if Russia maintains a naval base in Syria. So that isn't even an issue for me. If letting Russia keep that base in a post-Syria Assad regime and then a post-Assad Alawite semi-autonomous province keeps them on board, so be it.
Keep the focus on any deal being a transitional deal whose only function is to prevent short-term problems while keeping the ultimate objective of destroying the Assad regime--no matter how small it becomes--in mind.