Genocide is sometimes called the ’crime of crimes’. The word was coined by Raphael Lemkin in 1944, then declared an international crime by the United Nations General Assembly. In 1948, the Genocide Convention was adopted. As the first human rights treaty of modern times, it constituted a significant intrusion into what had previously been a matter exclusively of domestic concern. This explains the narrow definition of the crime of genocide. It requires proof of an intent to destroy a national, ethnic, racial or religious group. Only a half century after its adoption did the Genocide Convention take on real significance with inter-State cases being filed at the International Court of Justice and many prosecutions at the International Criminal Tribunals for the former Yugoslavia and Rwanda. The Convention requires that States Parties punish genocide but they are also required to prevent it, even when it takes place outside their own territory. More than 150 States have ratified the Genocide Convention. Genocide is also prohibited under customary international law. It is generally agreed that the duty to punish genocide is a peremptory norm of international law (jus cogens).

The post-First World War minorities treaties regime was an initial attempt by international law to address the rights of national and ethnic minorities. Its shorcomings prompted Raphael Lemkin, in his book Axis Rule in Occupied Europe, to propose a new category of international crime that he named genocide. The International Military Tribunal prosecuted acts of genocide using the category of crimes against humanity. Several of the defendants were convicted of acts aimed at destruction of Europe’s Jewish population. However, crimes against humanity were confined to acts associated with aggressive war. At the first session of the United Nations General Assembly in 1946, a resolution on genocide was proposed in order to address the peacetime atrocities that were neglected in the Nuremberg judgment. The resolution recognized genocide as an international crime and called for preparation of a convention.

This chapter introduces the United Nations War Crimes Commission and highlights its significance in relation to debates on war crimes during the Second World War. It is argued that the notion of war crimes at the start of the global conflagation was underdeveloped, and that a range of jurists, some of whom remain little known, made important contributions to developing legal knowledge that helped shape post-war war crimes prosecutions. The chapter explains the book’s focus on Poland and indicates how the Polish engagement with UNWCC can offer a fresh perspective on the emerging Cold War.

This chapter inquires how the historical context and biographical formative experiences shaped Lemkin’s intellectual career, leading to the definition of crimes of barbarity and vandalism, and later inventing the term ‘genocide’. It critically contextualizes Lemkin’s role at the dawn of international criminal law, showing the importance of his warnings and actions against the Holocaust, but also his romantic belief in the power of international law, his idealism, inconsistencies and contradictions. On one hand Lemkin raised a strong voice of advocacy for individual rights when criticizing the Soviet and the Italian penal codes in the 1920s; on the other, he became obsessed almost atavistically with the collective rights and the criminal intent to destroy ethnic, religious and national groups. In his emphasis on groups he departed from humanitarian law and human rights, both focusing on the individual. Lemkin’s life, private and public, was uneven; he simply could not find purpose in anything else than the Genocide Convention and its ratification.