From the German capture of Denmark and Norway, the Swedish overseas trade during World War II was mainly blocked by the battle of the Atlantic, but Swedish diplomats convinced Germany and the United Kingdom to let through a few vessels, mainly to the United States until their entrance into the war, and neutral countries in Latin America.
These transports, called lejdtrafiken, "the safe conduct traffic", were monitored by both powers, and ten of them were sunk during the war.
Though Sweden purchased American manufactured military aircraft early in the war, sales became prohibited by the US government in 1940.
[3] Historian Christian Leitz says that Sweden violated their neutrality by offering the United Kingdom ball bearings at a discount.
In 1938 SKF only charged the UK 74% of what they charged Germany and in 1943 only 68%,[4][5][page needed][6] whereas historian Eric Bernard Golson says that neutral powers such as Sweden maintained their neutrality and independence by offering economic concessions to the wartime powers to make up for their relative military weakness.