If all the things you cite are true then let's get the Congress to declare war and go win it.Its still associated with oil. That would be the free flow of Oil throughout the region to the rest of the world. So that is a National Interest to not have our enemies gain control of the flow of oil in the ME. Also, there is the Interest of Constraining the Russians. Then the Iranians.
Washington has a vested interest in Syria. The United States has maintained global security through its expansive military presence and its almost instant strike-force capability across the world. This has translated into a monopoly of deploying force abroad, often legitimized by UN resolutions or “coalitions of the willing.” That no other great power has been able to rival U.S. military capabilities—at least conventional capabilities—has deterred the likes of Russia and China from engaging in foreign adventures of their own. Russia’s intervention in Syria—the first outside of the geographical area of the former Soviet Union—is a precedent in the post–Cold War era, and is a direct challenge to America’s leadership in managing global security and maintaining a monopoly on the use of force. Should the United States allow Russia to dictate the outcome of the Syrian conflict, and expose American weakness, it could encourage a repeat in behavior elsewhere. Indeed, an increasingly assertive China is already testing America’s willingness and ability to confront its claims to the South China Sea. It also threatens to diminish the role of the UN Security Council, should great powers no longer deem it necessary to pursue UN channels to mandate military action. In terms of global security and great power relations, Syria should absolutely matter to Washington
But neither of these interests—confronting terrorism or containing Russia—necessarily equates to greater US military involvement, or war with the Assad regime. Determining interests is one matter, arriving at outcomes is another.....snip~
http://nationalinterest.org/feature/...t-18037?page=2