People ask why the United States is reticent in supporting the rebels in Syria. The United States has been reluctant in arming the opposition from the outset of the conflict, in contrast with the firm support of the Russian Federation to the Assad regime.
I think the answer may be found in the priority given by the Obama administration to the policy of reducing the nuclear arsenal with the Russian Federation. This policy takes into account the fact that Russia, while no longer the superpower the Soviet Union was, considers safeguarding its interests in Syria as the projection of it being a major power.