Transit of German troops through Finland and Sweden Union immediately requested a similar but more far-reaching concession from Finland, which invited the Third Reich to trade similar transit rights through Finland in return for weaponry lacked by the Finns. This was the first significant proof of a changed, more favorable, German policy vis-à-vis Finland, that ultimately would put Finland in a position of co-belligerence with Nazi Germany in the Continuation War against the Soviet Union (June 25, 1941 – September 4, 1944). After Denmark and Norway were invaded on April 9, 1940, Sweden and the other remaining Baltic Sea countries became enclosed by Nazi Germany and the Soviet
Finland–Russia border Finnish reindeer fence. Unlike other Western countries, the government of Finland did not protect illegal border crossers but returned them to the Soviet authorities if captured. Illegal border crossers had to get through Finland to e.g. Sweden in order to defect to the West. In the Moscow Armistice signed on 1944 between Finland, Soviet Union and United Kingdom, a small peninsula towards the Gulf of Finland, Porkkala, was rented to Soviet Union as a military base. This created in effect a southern border crossing to the Soviet exclave, operating all the way to 1956. Border crossings were in and .