Latvia states of Northern and Eastern Europe were divided into German and Soviet "spheres of influence". In the north, Latvia, Finland and Estonia were assigned to the Soviet sphere. A week later, on 1 September 1939, Germany and on 17 September, the Soviet Union invaded Poland. After the conclusion of the Molotov-Ribbentrop Pact, most of the Baltic Germans left Latvia by agreement between Ulmanis' government and Nazi Germany under the Heim ins Reich programme. In total 50,000 Baltic Germans left by the deadline of December 1939, with 1,600 remaining to conclude business and 13,000 choosing to remain in Latvia. Most of
Poland–Ukraine border of Poland-Russia, Poland-Lithuania, Poland-Belarus and Poland-Ukraine borders. Poland and Ukraine have confirmed the border on 18 May 1992. It is the longest of Polish eastern borders. The border became much more open compared to the Soviet times, when despite being part of the Eastern Bloc, crossing was very difficult. As the border was opened to mass traffic, the number of people crossing the Polish-Ukrainian border begun raising steadily since 1990, stabilizing around 2000s. Approximately 3 million Ukrainians crossed the border in the 1990s, annually. One of the peak numbers was recorded in 2001, with about 12 million people crossing the