 According to this theory, if man lacks a moral compass beyond the will to survive, and he was confronted by another species with a similar lack of morality, then the only possible moral result would be warfare.The fact that all pilots in the novel are women (in contrast to the infantry, which is entirely male) has been cited as evidence of progressive gender politics within the story, although the idea expressed by Rico that women are the motivation for men to fight in the military is a counter-example to this.A 1996 science fiction encyclopedia said that like much of Heinlein's fiction, "Starship Troopers" exemplified "macho male culture".