The Japanese need to experience the horrors they've done to others.
The Japanese in Korea brutally killed and tortured many Koreans. They made young Koreans into prostitutes and frequently raped women. In China, they killed and chopped off the heads of many Chinese men with no apparent reason. The Japanese massacred and raped many in the Rape of Nanjing. In short, the Japanese need to be taught a lesson on how to be humane to other races.