The convenience of Al-Qa`idah and Nusrah Front

It just occurred to me: by listing Nusrah Front as a terrorist organization, the US government has basically licensed all other Syrian armed groups to engage in all sorts of war crimes.  So all what an armed group has to do to get away with war crimes, is merely to fly the flag of Nusrah.  That is all what it takes.  So an armed group belonging to the Free Syrian Army umbrella, for example, can engage in a war crime, and then the next day issue a condemnation.  It is an unlimited license for war crimes.