Female characters and references to femininity throughout American war literature disrupt discursive and biological divisions of the masculine and feminine. In examining gender and war literature over the twentieth century, I propose an alternative genealogy of American war literature in which narratives since the end of the nineteenth century initiate two related patterns of gender representation that Vietnam War literature dramatically expands: they critique aggression, camaraderie, and heroism, rejecting these traditional sites of masculinity through desertion narratives, and they harness sentimentality, domesticity, motherhood, and penetration, embracing these traditional sites of femininity in ways that disrupt gender norms. By examining these sites of cross-gender identification through psychoanalytic, rhetorical, and feminist methods, I argue that narratives by Stephen Crane, Ernest Hemingway, Kurt Vonnegut, Tim O'Brien, Stephen Wright, and Larry Heinemann reveal the power of contemporary redefinitions of gender by absorbing feminist discourse into the performance of masculinity.