The European Union lifted its embargo earlier this week on sending weapons to Syria, thereby allowing its members to send arms to Assad's opposition, who have been facing a renewed assault from government forces. Shortly after the EU announced its decision, the Russian government confirmed that it would be sending the Assad regime anti-aircraft missiles, news that was not received well in Israel, whose defense minister said that Russian shipments to Syria (and possibly the pro-Assad Hezbollah) could be targets of Israeli strikes. Assad recently told a Hezbollah-owned TV station that the missiles had arrived.
To put it bluntly, a messy situation is being made much messier by intervention. And the U.S. hasn't even gotten involved. That could soon change. A bill authorizing the Obama administration to send weapons to "vetted" rebels recently passed out of the Senate Foreign Relations Committee; and, in the wake of unconfirmed reports that either Assad or the rebels used chemical weapons, and thus crossed a U.S.-established "red line," a bipartisan coalition is calling for intervention—if only to show Iran that when the U.S. establishes a red line, there are real consequences for crossing it.
Needless to say, there are also real consequences to wading into a complex civil war. The diplomatic, geopolitical, ethnic, and security considerations are vast and discouraging.
Diplomatically, some of the most significant barriers to intervention have been the Assad regime's relationships with Iran and Russia. More direct involvement in Syria could possibly derail negotiations with Iran over its nuclear program and could wreak havoc on America's ever-delicate relationship with Russia. While Assad alone does not pose much of a diplomatic threat, backing the rebels over the ruling regime would worsen America's already precarious relationships with Russia and Iran.
Another diplomatic matter to consider is that past interventions have been carried out in cooperation with international bodies. The intervention in Libya was done through the United Nations and NATO, whose leadership ruled out intervention in Syria back in March. Without the backing of an international body (the E.U., U.N., NATO etc.) any government that wants to send weapons to Assad's regime or intervene directly will could have its reputation tarnished and must be prepared to deal with the potential negative consequences. While the E.U. sanctions on sending arms to Syria may have been lifted, this is not the same thing as saying the E.U. backs member countries sending arms to Syria.
In addition to incurring diplomatic risks, intervention in Syria also could lead to further geopolitical destablization. Every one of Syria's neighbors has been affected by the civil war, be it by having to accommodate refugees or by having to deal with the conflict's overspill. The conflict has the potential to impact even more countries in the region, particularly by broadening the launch pad for jihadists who are abetting the rebels.
Nevertheless, interventionists are full of good ideas about how to "help" Syrians. Sen. John McCain (R-Ariz.) has argued that selective airstrikes like those used during the intervention in Libya could be used against the Assad regime. Elizabeth O'Bagy, political director for the Syrian Emergency Task Force, and Gen. Salim Idriss, leader of the Supreme Military Council of the Free Syrian Army, have asked for a no-fly zone to be put in place, another strategy that was implemented in Libya.
Would these tactics help bring down the Assad regime? Probably. That leaves America in the impossible position of predicting what Al Qaeda-backed rebels would do to the Syrian goverment, let alone Syrians who are members of religious minorities. The most prominent member of Congress to express these concerns is Sen. Rand Paul (R-Ky.), but he can't stop an intervention all by himself.
By itself, the complexity of the situation is not an argument against intervention. Yet, considering the questionable success of interventions in places like Libya, which appeared to all the world to be a much simpler operation, it's up to interventionists to sell the rest of us on yet another war. How exactly, will they separate the good rebels from the bad ones? How, exactly, will they keep the bad rebels from access stockpiles of Assad regime weaponry? What are the conditions of victory? If the rebels do route Assad, do we stick around and help them rebuild? If so, for how long?
Lastly: Why should we?