The concept of “law enforcement” in the context of the International Law of War

This article examines the influence of invoking concepts of policing in the interpretation and application of the international Law of War in war interim Japan using examples of the use of the toxic chemical teargas.<br> 　In the post-World War I world, attempts were again made to ban the use of toxic chemicals through international treaties, while at the same time the use of teargas by police agencies to maintain law and order and disrupt protest demonstrations was on the rise, mainly in the United States. In Japan, the Imperial Army brought into vogue the idea of using teargas by law enforcement agencies being an extraordinary humanitarian measure, through its acceptance of US military reasoning and its arming the police with teargas in 1930.<br> 　Meanwhile it was at the World Disarmament Conference（Geneva, 1932‐34）, for which preparations had been made since 1925, that the issue of the legality of teargas and its use by law enforcement was first raised internationally. Although a majority of the participating nations called for a total ban on the use of all toxic chemicals, the US delegation proposed that an exception be made for the use of teargas, especially by police agencies, resulting in the passing of a resolution banning teargas use during wartime, but permitting its use by law enforcement.<br> 　During both the Shanghai Incident（1932）and the Manchuria（Mukden）Incident（1934）, which occurred while the Conference was deliberating, the Japanese Army, aware of the necessity to abide by the Law of War and the tone of the Conference, limited itself to the use of smoke screen chemical weapons, while issuing carefully worded foreign reports about it. In contrast, the Guangdong Garrison occupying Manchuria and Army Headquarters in Japan interpreted the use of teargas as “domestic police action”, and thus problem-free in terms of international law. Moreover, the Imperial Navy in the case of “mob control” during the Shanghai Incident and the Army in suppressing “Chinese insurgents” in Manchuria went so far as to legitimize the use of teargas by deducing from the legal use by law enforcement its legal use in the war effort in China.<br> 　The author concludes that the cases in which teargas was tried to use and actually used by the Japanese military can be looked upon as attempts to legitimately link demands by the Army to employ chemical weapons both at home and abroad with the legal framework regarding the use of teargas by means of a flexible, fluid conceptualization of “maintaining law and order” applied under wartime conditions.