When the White House announced the appointments of Samantha Power to be Ambassador to the UN and Susan Rice to be National Security Advisor (only the UN position requires Senate confirmation) it was clear that Syria's days would be numbered, both of them being rabid humanitarian interventionists. What's surprising is that US meddling has happened so fast, before either is officially on the job. According to yesterday's New York Times the administration has concluded that the Syrian regime has used chemical weapons† and, therefore, the administration will begin to supply the Syrian insurgency with arms. A more stupid, dysfunctional US policy in the middle east could not be imagined. Things will not work out well.
The original sin in western meddling in the Yugoslav civil war was to recognize separatist Yugoslav Republics. The sensible thing would have been to let the Yugoslavs sort out their differences and then, after the dust settled, if there were viable, independent, post-Yugoslav entities, by all mean, recognize them. The precedent, however, has invited secessionist efforts generally, whether in Syria or elsewhere.
Syria may well shatter into a number of pieces along a mix of both sectarian and tribal lines. It's complicated. But — as even Congressional Research Service experts acknowledge in a recent report — assuming Mr. Assad is deposed the chances of "an opposition" coming peacefully into power are, to put it charitably, most remote. But then Mr. Assad might not be deposed but only diminished, by one or more breakaway regions. Rearranging the map of Syria is all well and good (in its current boundaries it hasn't been around for very long anyhow, the French mandate of Syria, a completely artificial construction, gaining independence only in 1946) except that if the US is taking sides we may find ourselves trying to stay on top of a more general rearrangement of the map of the middle east. At that point we'll really have to brush up on the differences between Shia and Sunni to stand a chance of making the correct decisions... a general middle east bloodbath being within the realm of possibility.
More practically, with the US arming one or another faction(s) of rebels it will be much, much more difficult, as if it wasn't difficult enough already, to engage Iran in any diplomatic negotiations over Syria's fate. The US, of course, doesn't want to engage Iran in the first place, and becoming a Syrian player will be one more huge reason not to. That's a pity because Iran props up Syria to the tune of about $3 billion a year and, given its own national security interests, Iran is not about to leave Syria to the wolves. If any kind of negotiated settlement were possible Iran would have to be involved. But if the US isn't interested in trying to find opportunities for a negotiated settlement then what we're doing is merely rolling the dice for war. It's a pitiful, childish way for a great country like ours to behave.
† It's perhaps by now a minor point but where are the bodies? If chemical weapons were used by government forces against insurgents, there must be bodies somewhere. Where are they? Even if the US government can't produce actual bodies surely it can say where, as in what city or town, the bodies are; where, that is, the alleged attack(s) took place. This is a question worth noting because in all modern wars allegations of massacres happen all the time; sometimes the allegations are a lie assembled from whole cloth, sometimes the allegations are made by those same people who, while claiming to be victims, are actually the perpetrators and, sometimes, the allegations are actually true. The only way for outsiders to know what's what is to double-check and, in this case, if the US government won't provide details, there is absolutely no good reason to believe the allegations.