The military is a hierarchical and pervasively regulated society in which individuals can exert tremendous influence over subordinates. Military codes in the United States and elsewhere vest tremendous discretionary power in commanders. “Command influence” occurs whenever a superior influences the action of some participant in the military justice process and may be lawful or unlawful. The US Congress has put in place a variety of protections against unlawful commander influence, but the issue remains. ‘Command influence, lawful and unlawful’ suggests that even with structural changes that reduce the power of commanders, there will inevitably be room for overreaching, and vigilance will continue to be required to keep it in check.