I imagine Dempsey is a good soldier. Sucks when your boss is the President and that people hang on every word looking for some hidden meaning or agenda. He has spoken his peace regarding Syria, and it falls in line with what seems to be the prevailing consensus here on the prune. Yet, he has his marching orders and I would imagine he will do exactly what he is told to the best of his capabilities despite his stated misgivings.
I see no need to trample on the General for following orders.