In "Defender of the Faith," what does Sergeant Marx's final statement that he has accepted his fate mean? What is his fate?

In context, Marx is referring to his position in the military, and the anger and dislike he inspires in the young men he trains for war. This and war are his fate. Thus, we can infer from the text that he has accepted his part in sending the young men to war, as well as the resentment he inspires because of his position.