In today's military we say, "I will never leave a fallen comrade to fall into the hands of the enemy." We don't say, "he knew what he signed up for." And this is not a contemporary idea. In fact, it's long been woven into the fabric of the U.S. military. In his 1959 military classic Starship Troopers, Robert Heinlein characterized it by saying, "You knew with utter and absolute certainty that, as long as you were still alive, the Lieutenant would not get into the retrieval boat without you."