The British influence on the laws of war and the punishment of war criminals: from the Grotius Society to the United Nations War Crimes Commission

At the end of World War I, the punishment of violations of the laws of war became of greater importance and the subject of heated debate than had hitherto been the case, not only for the British Government and its Allies, but also for members of the newly founded Grotius Society who had already worked on the topic during the war. The British Government proposed a number of innovative ideas that were a radical departure from the existing lex lata governing the laws of war. The most notable among them were that violations of the laws of war give rise to individual criminal responsibility for the actual perpetrators and high ranking officials, and even Heads of State, who order or fail to prevent them, and that injured belligerents have the right to try persons belonging to the enemy for such violations, including after hostilities have ceased. These ideas were far from uncontroversial. Yet they ultimately brought about a landmark change in the customary laws of war and were relied upon by Britain and its Allies during World War II. To date, the influence that Britain had in bringing about this change has been given little consideration in existing scholarship. This chapter uses a range of primary and secondary sources, including archival materials, in order to examine the pivotal role that Britain played. It also examines the work of members of the Grotius Society, on whose innovative ideas the British Government had relied.