Armed forces must be disciplined, but two bodies of international law relating to military discipline are in tension. On the one hand, international humanitarian law requires armed forces to employ robust disciplinary measures to deter and address military misconduct. On the other hand, some international human rights law scholars recently singled out military disciplinary measures as insufficiently protective of soldiers from unfair treatment. Advocates of this new approach proposed to remedy disciplinary unfairness by permitting soldiers to opt out of disciplinary proceedings and elect military criminal trials instead. This Article critically examines four of the underlying assumptions of this new approach. It argues that interlinking disciplinary sanctions with penal sanctions through such an opt-out right is a mistake, and that there is an enduring role for both in regulating the behavior of armed forces.