Sweden during World War II maintained a policy of neutrality. When the Second World War began on September 1, 1939, the fate of Sweden was unclear. But by a combination of its geopolitical location in the Scandinavian Peninsula, successful realpolitik maneuvering during an unpredictable course of events, and a dedicated military build-up after 1942, Sweden managed to maintain its official neutrality throughout the war.
At the outbreak of hostilities, Sweden had held a neutral stance in international relations for more than a century, since the end of the Napoleonic Wars in 1815. Twenty nations held a policy of neutrality in September 1939, but only seven other European nations found themselves capable, like Sweden, of officially maintaining this stance throughout the entire war: these were Ireland, Portugal, Spain, Andorra, Liechtenstein, Vatican City and Switzerland. The Swedish Government made a few concessions, and sometimes breached the nation's neutrality in favor of both Germany and the Western Allies. During the German invasion of the Soviet Union, Sweden allowed the Wehrmacht to use Swedish railways to transport (June–July 1941) the German 163rd Infantry Division along with howitzers, tanks and anti-aircraft weapons and associated ammunition, from Norway to Finland. German soldiers traveling on leave between Norway and Germany were allowed passage through Sweden — the so-called permittenttrafik. Iron ore was sold to Germany throughout the war. And for the Allies, Sweden shared military intelligence and helped to train soldiers made up of refugees from Denmark and Norway, to be used in the liberation of their home countries. It also allowed the Allies to use Swedish airbases between 1944 and 1945.
Sweden also became a refuge for anti-fascist and Jewish refugees from all over the region. In 1943, following an order to deport all of Denmark's Jewish population to concentration camps, nearly all of Denmark's 8,000 Jews were brought to safety in Sweden. Sweden also became a refuge for Norwegian Jews.