Why the Nazis wanted Sweden to remain free?

Answer 1

The Nazis did not care whether Sweden remained free. So long as Sweden cooperated with the Nazis, the Nazis were relieved of the necessity to invade Sweden. The Nazi regime was completely dependent on Swedish iron ore, from which they made steel to fabricate into all the implements of war - tanks, guns, artillery, artillery ammunition, ships, submarines, and so on. Had the Swedes refused to continue to provide this iron ore the Nazis certainly would have invaded Sweden to secure the supply. The Nazis had a plan on the books for the invasion of Sweden, but never had to put it into operation, as the ore continued to flow into Germany. Additionally the Swedes supplied the Nazis with crucial machined parts for their war industry, including ball bearings, and allowed the Germans to use their excellent design of the Bofors 40mm anti-aircraft machine cannon (interestingly the Allies used this identical weapon, but had to secure the plans and designs through espionage).