As the Russians insist that the Assad government is the only legitimate government, all anti-Assad fighters — ISIS, al Qaeda-related, or U.S.-backed or Turkish-backed “moderates” — are, by definition, terrorists.
Russian — and in particular Syrian — tactics are appalling. Washington would rather not be associated with them, but has a horror of the vacuum that might emerge if Assad is swept aside. Mainly, the U.S. has hung its hat on the International Syria Support Group. The U.S. is muddled, as usual, without a clear goal, clear allies or fixed positions beyond support for a “political process.”
The U.S. is looking less and less relevant, as historic Great Powers do what they have historically done best — fight for their national interests as they define them. President Obama appears to be conceding the lead to Russia and Russian aims.