Is it the loss of a Democrat majority in the House? The Republicans stubbornness and inability to compromise? The continuous barriers against Obama's attempts to pass certain Acts? Or is it because the House is filing a law suit against him? (Yes really). Clearly all of these things coupled together worsen the situation, but Obama's main problem is that he's just too nice to be President.
I'm not denying that the war in Syria is a hell on earth for it's citizens, or that there have been war crimes committed against them. Though I suspect our government's push for arms sales to Syrian opposition forces may have less to do with the atrocities and inequalities of a foreign war and more to do with financial concerns closer to home.