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
Finland–Russia border which there is a maritime boundary between the respective territorial waters, terminating in a narrow strip of international waters between Finnish and Estonian territorial waters. The first border treaty concerning this border was signed in Nöteborg in 1323, between Sweden (to which Finland belonged) and the Novgorod Republic. The Treaty of Teusina in 1595 moved the border eastward. In conclusion to the Ingrian War, Sweden gained a large tract of land through the acquisition of the Nöteborg fortress, the Kexholm and its large province, southwest Karelia and the province of Ingria in the Treaty of Stolbovo (1617). The Treaty of