Japan paid a very heavy price for their aggression and the unspeakable cruelty they inflicted. We made them change their ways. Right now the world does hand wringing about what to do about the Palestinian “problem”. If one wants peace you have to make peace and sometimes the endeavor ain’t pretty.
To quote Mao, “Peace comes out of the end of a rifle barrel.” It is estimated he killed 80 million of his own people, historians can only guess the number.