International agreements define war crimes and make them punishable by law. Determining responsibility for war crimes involves putting war criminals on trial and deciding on appropriate punishments. However,in the war crimes tribunals that were set up after World War II, the Far East International War Crimes Tribunal that tried Japanese war criminals in Tokyo was not as rigorous as the Nuremburg trials in which Nazi war crimes were judged. As a result, there are many Japanese war crimes that have not yet been dealt with.

For example, the Emperor was not put on trial and the issue of his responsibility for the War has not been pursued, even though he was the head of the Imperial Army during the War. In addition, the use of toxic gases during the war with China and experimentation on live subjects by Unit 731 were certainly war crimes, yet those responsible were never brought to justice because the American authorities decided it was not in their best interests to prosecute them. Thus, there are still many victims of war crimes not only in Japan but also in many other places around the world, especially East Asia, who have not been compensated and are seeking redress through lawsuits and other means.