Why must prisoners of war receive the same range of penalties as members of the detaining power's armed forces?

Under the third Geneva Convention of 1949, prisoners of war must be subject to the same range of penalties as members of the detaining power's own armed forces for the same offense.1

This requirement is rooted in the fundamental principle of humane treatment and the legal status of captives. By ensuring that prisoners are not subjected to harsher or arbitrary punishments than those applied to a detaining power's own military personnel, the law prevents discriminatory treatment and ensures that justice is administered through established, predictable judicial processes.21

Furthermore, this standard reinforces the law of war by maintaining that prisoners are not to be treated as property or subjects of reprisal, but as individuals entitled to specific protections throughout their captivity. When a prisoner is tried for an offense, they must be judged by a military court, unless the laws of the detaining power allow for members of its own armed forces to be tried by a civil court for the same act.321