We Americans may be getting into our THIRD Middle-Eastern conflict in the last decade, if President Obama's speech this morning is any indication. I think what's going on in Syria is atrocious, but there are so many really sticky factors therein that I think American involvement would prove even more of an entangling mess than Iraq and Afghanistan combined.
We should know historically that small countries are not necessarily easier to subdue than larger ones (Greece v. the Persian empire, anyone?)--and, besides, there's much more opportunity for "bleed over" into adjacent countries. Whereas Afghanistan and Iraq have geographically generous proportions, Syria is comparatively small. But it's nestled cheek by jowl with some of the most diplomatically delicate areas in the Middle East. Sure, Afghanistan has Pakistan and Iran on either side, and those places have their own problems, and Iraq has Iran and Saudi Arabia and Kuwait, but there was still plenty of desert on all sides so as to avoid accidental incursions by Allied forces into others' territory. Syria, on the other hand, is framed by Turkey, Iraq, Lebanon, Jordan, and our one steady ally, Israel.
Although thousands of wannabe muhadejeen (Did I spell that right? Blogger doesn't think so) from abroad streamed into aid their coreligionists in Iraq and Afghanistan against the American-led invasion (with clearly documented ill effects on our military), there wasn't an ongoing official call-up of volunteers from that old anti-Israeli bugbear, Hamas, to support the regime, nor was either country directly allied with Russia (which has maintained naval bases--its beloved, long-sought "warm water ports"--on the Syrian coastline since Soviet days). Afghanistan had given the USSR its own bloody nose and its resistance fighters a decade of in-cave military experience long before the Americans decided (for dubious reasons) to invade (only to depart almost as ingloriously as their Russian predecessors, and with about the same long-term effect on the infrastructure and intertribal tensions).
I grant you Assad is a real bastard. But he's been in power for decades, committing atrocities against his own people throughout that time (albeit not quite on today's scale, but then again, they weren't taking this level of action against him at the time, either), and the US has turned a blind eye. He's a murderer, using chemical weapons (really, rather than just rumored to be capable of it, like Saddam) against women and children. I think this should be stopped. But do we have to do it? There are so many evil things in this world (even here at home!), and is it really the US role to attempt to quell them all? And certainly, shouldn't we ask if it is even possible?
We tend to look back to the situations during World War II (and the Korean War, for those who know about it) as examples of times America intervened and "saved the day" (with a little help from our friends...), and yet we haven't successfully reproduced the positive results of those "good ol' days" since 1953! Sixty years of repeated failure, in "limited war" after "limited war" is not a good track record. I would suggest that Vietnam, Lebanon, Iraq and Afghanistan (have I forgotten any?) all illustrate an aspect of what is and has been fundamentally wrong with American diplomatic-military foreign policy: sending troops into ethnically messy ongoing conflicts where there is no clear extra-territorial aggressive intent on the part of the "bad guys".
Since 1953, there have been repressive, murderous, and even genocidal regimes all over the world: in Cambodia, in several parts of Africa, in North Korea. Some of these have been in place for much longer than Assad. Yet we let them be militarily. Quite a few have been and are cozy with the USSR/Russian Federation, and even though we Russianists are thin on the ground these days, at least in the past Americans had enough sense to avoid direct conflict with that large and well-armed (and now economically recovered) country.
Unless Israel or Turkey is directly attacked by Syria, subjected to outright invasion which the military materiel we've given by the boatload to both cannot handle without additional help from us, I say let the US stay out of direct involvement in that war. Support the rebels, if we can afford it (which I have begun to question, even on this limited scale), and shout "Vive Le France" and let the French (who have their own method of dealing with their former colonies), deal with the mess. After all, the French and the Russians have faced off before, and each are less inclined than Americans to be hyper-concerned about collateral damage, which would doubtless handicap the well-meaning, but ill-informed American ground forces.
Especially as Egypt falls further into chaos, I see no need for Americans to move closer to the Armageddon area, diplomatically or geographically. And if we aren't going to occupy and colonialize clearly and long-term, I don't see democracy developing post-war in places that have never tasted even a hint of its bittersweet fruit (which both Germany and South Korea had done, pre-wars). Especially in a land as ethnically and religiously diverse as Syria (India, the world's largest democracy, a country of huge ethnic and religious diversity, had two centuries of occupation by the British to inculcate some appreciation for the benefits of representative government--one mostly denied to Indians until Gandhi led the civil rights/independence movement--and it still occasionally suffers from sectarian violence), I don't foresee the advent of democracy for many generations to come. And aren't we going to have to "do something" about Russian ally Iran sometime in the near future? Why don't we save our limited resources for dealing with that larger (and potentially more economically devastating) threat?