This argument cannot be applied selectively. Either that's the case, or it's not. If that's the case, look another way and Donbass seps will go west to the nearest big river, establish a land bridge to Crimea and Transdniestr and tada. If that's not cool, then whatever happens in Syria isn't cool either. U.N. is not a factor - US doesn't give rats ass about the U.N. when it doesn't approve of whatever it is that US wants at the time, so no reason to wave that flag at othat times. On the grand scheme of things it really is whatevs, we can support or not support certain geopolitical events, but it's not like that's gonna change them.