There is a certain cold, hard logic to this idea: If Syria is going to become a failed state, better to keep the various jihadist groups on their back foot fighting U.S.-backed rebels instead of consolidating their control over more territory. However, this ignores several critical questions: Are we sure the "good guys" really are good? Opposition forces may claim allegiance to Western principles when beseeching international donors, but good intentions can quickly melt away in the face of a struggle for power.
Secondly, and more problematic, is that once weapons enter Syria, the United States has zero capacity to ensure that only "good guys" get them. Weapons are fungible. They can be stolen, diverted, plucked from the bodies of fallen soldiers or transferred from America's preferred parties to jihadists with their own aims. If sophisticated U.S. arms flow into Syria, a black market for those weapons will no doubt flourish, and al-Qaeda will be buying.
4. They've used chemical weapons
President Obama himself gravely warned that the use of chemical weapons by the Assad regime would be a "game changer" as far as American policy was concerned. With the administration now acknowledging that those weapons were used, it begs an admittedly blunt question: What difference does it make?
The administration was willing to let over 70,000 Syrians die by bullet and bomb without a direct intervention. Does a sarin gas attack really change the strategic calculus as far as American interests are concerned? Moreover, what is the administration supposed to do? Writing in Bloomberg, Jeffrey Goldberg suggests sending special forces, enforcing a no-fly zone and openly arming the rebels -- none of which are remotely sufficient to adequately secure dispersed stockpiles of chemical weapons, let alone secure the country. Moral outrage at the use of these weapons is justified, but it shoudn't blind us to the fact that bombing Assad out of power won't ensure a stable, secure aftermath for the people we claim to be protecting. All the problems inherent in toppling the regime remain -- whether Syrians have fallen to chemical attacks or more conventional forms of butchery.
Some may argue that American credibility is now on the line after the White House drew a red line. It's true that the administration's future threats will likely be discounted, but that's a smaller price to pay than the steep costs that would be incurred by directly intervening in Syria's civil war. Compounding a small error with a much larger one is no way to restore American credibility.
The End Game
What unites the four bad arguments for American involvement in Syria is that they treat the fall of Assad as the end of American (and Syrian) troubles, when in fact it would be just the beginning. All of the supposed gains that flow from toppling Assad can only occur if a post-war state can be cobbled together that is secure and institutionally oriented toward the West. Many pundits and analysts have spent an inordinate amount of time lobbying for "leadership" (i.e. an intervention) without addressing the crucial questions of what follows in the aftermath. To wit: Who will secure Syria when Assad falls? Who will fund a post-Assad government? What will stop Iranian influence from hijacking a new Syrian government? Who will protect the Alawite minority in Syria from reprisal killings? Who is responsible for targeting (or at least disarming) jihadist movements inside the country?
And consider this: What makes proponents of a U.S. intervention in Syria believe Washington has the werewithal to restore the country to some semblence of stability? In Iraq, the U.S. spent trillions of dollars, thousands of lives and, in the case of Afghanistan, over a decade trying to nation build with results that could best be described as modest. Have we suddenly become more capable, wealthier and fluent in the various tribal and sectarian intricacies of the Muslim world to make the third time the charm?