[1][2] Since the 1977 Additional Protocol I to the Geneva Conventions (AP 1), reprisals in the laws of war are extremely limited,[3] as they commonly breach the rights of non-combatants.
The tribunal emphasized that before reprisals could be legally undertaken, a number of conditions had to be satisfied: The German claim that it had acted lawfully was rejected on all three grounds.
In December 1920 the General Officer Commanding-in-Chief (Nevil Macready) informed the British Cabinet that Military Governors in martial law areas had been authorized to conduct reprisals in response to attacks on the military and police, under these conditions:[8] Punishments will only be carried out on the authority of the Infantry Brigadier, who before taking action will satisfy himself that the people concerned were, owing to their proximity to the outrage or their known political tendencies, implicated in the outrage, and will give specific instructions in writing, or by telegram to the officer detailed to carry out the operation.
[9] The official 1940 American Rules of Land Warfare stated that "commanding officers must assume responsibility for retaliative measures when an unscrupulous enemy leaves no other recourse against the repetition of barbarous outrages.
"[9] Both Rogers and Bennett write that "[s]tate practice in the Second World War was characterised by, among other factors, the doctrine of belligerent reprisal.