How did the world community respond to genocides after world war 2

Towards the end of World War II, Raphael Lemkin, a lawyer of Polish-Jewish descent, aggressively pursued within the halls of the United Nations and the United States government the recognition of genocide as a crime. Largely due to his efforts and the support of his lobby, the United Nations was propelled into action. In response to Lemkin's arguments, the United Nations adopted the term in 1948 when it passed the "Prevention and Punishment of the Crime of Genocide".