World War II population transfers

Mass evacuation, forced displacement, expulsion, and deportation of millions of people took place across most countries involved in World War II. A number of these phenomena were categorised as violations of fundamental human values and norms by the Nuremberg Tribunal after the war ended. The mass movement of people – most of them refugees – has either been caused by the hostilities, or enforced by the former Axis and the Allied powers based on ideologies of race and ethnicity, culminating in the postwar border changes enacted by the international settlements. The refugee crisis created across formerly occupied territories in World War II provided the context for much of the new international refugee and global human rights architecture existing today.

Belligerents on both sides engaged in forms of expulsion of people perceived as being associated with the enemy. The major location for the wartime displacements was the East-Central and Eastern Europe, although Japanese people were expelled during and after the war by Allied powers from locations in Asia including India. The Holocaust also involved deportations and expulsions of Jews aside from the subsequent genocide perpetrated by Nazi Germany under the auspices of Aktion Reinhard.

Following the invasion of Poland in September 1939 which marked the beginning of World War II, the campaign of ethnic "cleansing" became the goal of military operations for the first time since the end of World War I.

The United Nations Relief and Rehabilitation Administration was set up in 1943, to provide humanitarian relief to the huge numbers of potential and existing refugees in areas facing Allied liberation. UNRRA provided billions of US dollars of rehabilitation aid, and helped about 8 million refugees. It ceased operations in Europe in 1947, and in Asia in 1949, upon which it ceased to exist. It was replaced in 1947 by the International Refugee Organization (IRO), which in turn evolved into United Nations High Commissioner for Refugees (UNHCR) in 1950.

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