Besides the already-important attempts to punish harshly anyone (with a trial) who had been in the upper echelons of Nazi government vis-รก-vis the Nuremberg Trials, there was also an international push to define and condemn genocide. This resulted in the Convention on the Prevention and Punishment of the Crime of Genocide, adopted on 9 December 1948, and which went into force in 1951.
Among the portions that were meant to prevent and punish genocide are the provisions is a commitment to enact legislation punishing genocide within contracting nations, agreement to extradite anyone who had attempted or committed genocide and fled, opportunity to appeal to the UN bodies and the UN Charter to handle genocide, and an agreement to try via state judiciaries or international judiciary proceedings (if the contracting parties agree to an international proceeding) anyone accused of genocide.