The climax of this policy of ethnic cleansing came in the wake of World War II, when-based on the erroneous principles of collective guilt and collective punishment-perhaps as many as sixteen million germans were compelled to leave their ancient homelands in east - central and southeastern europe. at the yalta and potsdam conferences, the leaders of the victorrious great powers agreed to truncate Germany and transfer Eastern Germany's ethnic German population to the remaining portions of the country. they likewise agreed to expel the 3.5 million Sudeten Germans from the mountainous frontier regions of Bohemia and Moravia (the Czech state )- a region that these Germans had inhabited for over seven centuries. A similar policy of expulsion was also applied, although less stringently, to the smaller German ethnic to communities of Hungary, Romania, and Yugoslavia. All in all, 16.5 million Germans may have fallen victim officially sponsored policy of ethnic cleansing.