This essay examines the instrumentalization of emotions and affect—especially of happiness—in evaluating the outcome of counterinsurgencies. Traditionally, metrics and statistics have been utilized as the main means of measuring the achievement of military goals. However, given the centrality of noncombatant populations in counterinsurgencies, military theorists have increasingly sought to incorporate culture and intuition in their arsenal of tactics. Focusing on the development of the uses of affect by the United States, this study illuminates the ongoing tensions between political and military actors who seek to promote specific forms of knowledge—statistical versus qualitative—about war. This essay points to the sedimentation of colonial practices around affection and disaffection, and of colonial intimacy in these counterinsurgency practices. By drawing on the writings and memoirs of counterinsurgents and on official documents drawn up by the US military, the essay situates the current US practices at the point of convergence between contemporary practices of governmentality and historical colonial discourses.