Operation Weserübung's effects on Sweden became strategically encircled by the German-Soviet pact. Since the Baltic states; Estonia, Latvia, and Lithuania; had been forced to accept "limited" Soviet forces on their soil, in the autumn of 1939, they were de facto more or less in a state of occupation. For Sweden and Finland, this meant that the only possible trade route to nations other than Germany and the Soviet Union, was through Petsamo harbour, in the far north of Finland. This seriously hampered the supply situation in both these nations. It also meant that an invasion of Sweden could be launched from almost any direction. Sweden
Germany–Poland border the Slavic tribes. Over several centuries, it has moved eastwards, stabilized in the 14th century, and disappeared in the late 18th century with the partitions of Poland, in which Poland's neighbors, including the Kingdom of Prussia, annexed all of its territory. In 1871 Prussia became part of the German Empire. After Poland regained independence following World War I and the 123 years of partitions, a long German-Polish border was settled on, long (including a border with East Prussia). The border was partially shaped by the Treaty of Versailles and partially by plebiscites (East Prussian plebiscite and the Silesian plebiscite, the