Based on a new Army War College study of unit cohesion in the Iraq War, Wong et al. argue that successful unit performance is determined by social cohesion (the strength of interpersonal bonds among members) rather than task cohesion (a sense of shared commitment to the unit’s mission). If correct, these conclusions have important implications for scholarship as well as for numerous U.S. military policies such as the Unit Manning System. However, this article disputes their contentions. Wong et al. ignore a large body of empirical research on military and nonmilitary groups showing that social cohesion has no independent impact on performance. They provide no evidence for the representativeness of the interview quotes they cite as evidence for the reliability or validity of their measures. Their methodology fails to meet social science standards for causal inference (e.g., ruling out causal rival factors).