The Vacuum theme goes like this: The Middle East may be in flux, but our threat environment remains frozen in time — a Nineties warp in which Iran, singularly, is the root of all evil. In Syria now, we have a golden opportunity to hand the mullahs a crushing defeat. All we need to do is commit to toppling their client, Bashar al-Assad. Media spin thus suggests that Assad’s minority Alawite regime is responsible for each of the 70,000 killings and half a million displacements that Syrians have endured since the civil war began — as if the Sunni majority, led by the local Brotherhood affiliate with al-Qaeda as the point of its spear, were not carrying out reciprocal mass murders and an anti-Christian pogrom.
in other words, in this part of the world, the enemy of my enemy is not my friend. We have lots of enemies in the region, but none are on "our side" (whatever that means) just because they are fighting each other. They all believe in Islamic supremacy and all desire to conquer the world and impose Sharia on all of it. They are not fighting for freedom and liberty and justice. They are fighting to determine who will become the supreme dictator in their global theocracy.
Backing any of them is just plain stupid unless the US has something clear to gain from doing so. And toppling one dictator to make room for another is neither clear or a gain.
As for those who claim the US should intervene for humanitarian reasons, what exactly does that mean? Why destroy one mass-murdering regime in order to make room for another? How does that improve anything? The momentary fuzzy feeling that you were finally able to "do something" is hardly sufficient justification for going to war.
The time where military intervention couldn't stopped radical Islam passed in the 70's when we surrendered to Khomeini. Today, Pandora's box has opened and evil has spread worldwide. It will require nothing less than a sustained world-wide effort to eliminate this mess, involving going to war with dozens of nations and massive amounts of internal law enforcement (without politically-correct favoritism) in the rest of the world. Since that's never going to happen, could the leaders of the so-called "free world" at least decide to stop making the problem worse?