Definitions of Japanese war crimes There are differences from one country to another regarding the definition of Japanese war crimes . War crimes may be broadly defined as unconscionable behavior by a government or military personnel against either enemy civilians or enemy combatants . Military personnel from the Empire of Japan have been accused and / or convicted of committing many such acts during the period of Japanese imperialism from the late 19th to mid - 20th centuries . They have been accused of conducting a series of human rights abuse s against civilians and prisoners of war ( POWs ) throughout east Asia and the western Pacific region . These events reached their height during the Second Sino - Japanese War of 1937 – 45 and the Asian and Pacific campaigns of World War II ( 1941 – 45 ) . In Japan itself , the description of particular events as war crimes — and specific details of these events — are often disputed by Japanese nationalists , such as " Tsukurukai " ( Society for History Textbook Reform ) . Such organisations and their activities are a subject of controversy and are alleged to be examples of historical revisionism . International law . Although the Geneva Convention s have , from 1864 onwards , provided the standard definitions of war crimes , the Empire of Japan never signed the Geneva Conventions . However , many of the alleged crimes committed by imperial personnel were also violations of the Japanese code of military law , which Japanese authorities either ignored , or failed to enforce . The empire also violated provisions of the Treaty of Versailles such as article 171 , which outlawed the use of poison gas ( chemical weapons ) , and other international agreements signed by Japan , such as the Hague Conventions of 1899 and 1907 which protect prisoners of war ( POWs ) . According to historian Akira Fujiwara , Hirohito personally ratified , on 5 August 1937 , a proposition by his Army chief of staff Prince Kan ' in to remove the constraint of those conventions , on the treatment of Chinese prisoners . Japan and international treaties . In Japan , the term " Japanese war crimes " generally refers to cases tried by the International Military Tribunal for the Far East , also known as the Tokyo Trials , following the end of the Pacific War . The tribunal did not prosecute war crimes allegations involving mid - ranking officers or more junior personnel . Those were dealt with separately in other cities throughout the Asia - Pacific region . The Japanese government takes the position that as Japan was not a signatory to the Geneva Conventions , it violated no international law . For the same reason , the Japanese government also takes the view that Allied states did not violate the Geneva Convention in acts committed against Japanese personnel and civilians , including the internment of ethnic Japanese citizens of Allied countries , the fire bombing of Tokyo , the atomic bombings of Hiroshima and Nagasaki , and instances of Japanese POWs being killed or otherwise brutally treated . The Japanese government did sign the Kellogg - Briand Pact in 1929 , thereby rendering its actions in 1937 – 45 liable to charges of crimes against peace , a charge which was introduced at the Tokyo Trials to prosecute Class - A War Criminals . ( Class - B War Criminals are those found guilty of war crimes " per se " , and Class - C War Criminals are those guilty of crimes against humanity . ) However , any convictions for such crimes are not required to be recognized by the Japanese government , as the Kellogg - Briand Pact did not have an enforcement clause , stipulating penalties in the event of violation . The Japanese government accepted the terms set by the Potsdam Declaration ( 1945 ) after the end of the war . The declaration alluded , in Article 10 , to two kinds of war crime : one was the violation of international laws , such as the abuse of prisoners of war ( POWs ) ; the other was obstructing " democratic tendencies among the Japanese people " and civil liberties within Japan . Japanese law . Japanese law does not recognize those convicted in the Tokyo Trials and other trials as criminals , despite the fact that Japan ' s governments have accepted the judgments made in the trials , and in the Treaty of San Francisco ( 1952 ) . This is because the treaty does not mention the legal validity of the tribunal . In the Japanese text , the word used for " accept " is " judaku " , as opposed to the stronger " shounin " ( " to approve " ) . Those convicted have had no ability , under Japanese law , to appeal , as the Tokyo Tribunal and other war crimes courts have no standing in Japanese law . Under normal circumstances it violates a number of fundamental principles of modern legal procedure to punish someone whose crime and penalty were defined only after the fact . Had Japan certified the legal validity of the war crimes tribunals in the San Francisco Treaty , this might have resulted in Japanese courts reversing such verdicts . Any such outcomes would have created domestic political crises and would have been unacceptable in international diplomatic circles . The current Japanese jurists ' consensus regarding the legal standing of the Tokyo tribunal is that , as a condition of ending the war , the Allies demanded a number of conditions including the execution and / or incarceration of those whom they deemed to be responsible for the war . These people were defined as guilty by a tribunal organized by the Allies . The Japanese government accepted these demands in the Potsdam Declaration and then accepted the actual sentencing in the San Francisco Treaty , which officially ended the state of war between Japan and the Allies . Although the penalties for the convicted , including execution , can be regarded as a violation of their technical legal rights , the constitution allowed such violations if proper legal procedure was followed , in the general public interest . Therefore , any such execution and / or incarceration is constitutionally valid , but has no relationship to Japanese criminal law . Hence those convicted as war criminals are not defined as criminals in Japan , although their execution and incarceration is regarded as legally valid . International definitions . Outside Japan , different societies use widely different timeframes in defining Japanese war crimes . For example , the annexation of Korea by Japan in 1910 was followed by The abolition of the traditional class system by Joseon and modernization against the Korean people . Thus , some Koreans refer to " Japanese war crimes " as events occurring during the period shortly prior to 1910 to 1945 . Events such as the March 1st movement where 7 , 000 people were killed and the murder of Empress Myeongseong are considered war crimes in Korea . By comparison , the United States did not come into military conflict with Japan until 1941 , and thus Americans may consider " Japanese war crimes " as encompassing only those events that occurred from 1941 to 1945 . A complicating factor is that a minority of people in every Asian and Pacific country invaded by Japan collaborated with the Japanese military , or even served in it , for a wide variety of reasons , such as economic hardship , coercion , or antipathy to other imperialist powers . Many Koreans served in the Imperial armed forces . The Formosan Army , which was part of the Imperial Japanese Army , was recruited from ethnic Chinese men on Formosa . The Indian National Army , under Subhas Chandra Bose , is perhaps the best - known example of a movement opposed to European imperialism , which was formed during World War II to assist the Japanese military . Prominent individual nationalists in other countries , such as the later Indonesia n president , Suharto , also served with Japanese imperial forces . The Burmese nationalist leader Aung San initially sided with the Japanese , forming the Burma National Army , but turned against them in early 1945 . In some cases such non - Japanese personnel were also responsible for war crimes committed by the Empire of Japan . B . V . A . Roling , the Dutch justice at the Tokyo trials , noted how " many of the commanders and guards in POW camps were Koreans [ as ] the Japanese apparently did not trust them as soldiers . " Korean guards , he added , were often said to be " far more cruel than the Japanese . " One Korean described abject Allied POWs : " now I have seen how depraved and worthless the white man is . " For political reasons , many non - Japanese personnel in the Imperial armed forces were never investigated or tried after 1945 . In South Korea especially , it is alleged that such people were often able to acquire wealth by participating in exploitative activities with the Japanese military . It is further alleged in South Korea that some former collaborators have covered up " Japanese " war crimes in order to avoid their own prosecution and / or exposure . It has been argued that acts committed against people subject to Japanese sovereignty cannot be considered " war crimes " . The issue of Japan ' s " de jure " sovereignty over places such as Korea and Formosa , prior to 1945 , is a matter of controversy . Japanese control was accepted and recognized internationally and was justified by instruments such as the Treaty of Shimonoseki ( 1895 , which included China ' s cession of Taiwan ) and the Japan – Korea Annexation Treaty ( 1910 ) . The legality of the Japan – Korea Annexation Treaty , in particular , is in question because it was not signed by the Korean head of state ; it was signed by government ministers . The native populations were not consulted on the changes in sovereignty , nor was there universal acceptance of such annexations . There was ongoing resistance to Japanese invasions and — in any case — war crimes may also be committed during civil wars . ( See Korea under Japanese rule and Taiwan under Japanese rule for further details . ) There are also allegations that war crimes were committed even after the Empire of Japan officially surrendered on August 14 , 1945 . For instance , it is believed that Allied prisoners of war who survived the Sandakan Death Marches , in North Borneo , were killed up to two weeks after the Emperor signed the surrender document .