

Left picture - Swedish volunteers arriving Northern Finland during the Winter War. You may notice some civilian boys watching the Swedes getting ready. The car might be an ambulance vehicle. Right picture - a Swedish soldier nursing a Finnish baby, a war refugee in Sweden during the Lapland War 1944-1945. Both pictures: SA-kuva, AI colorized by Jopa's computer.
Officially Sweden remained neutral throughout the WWII. However, there are several events - minor and major - indicating this statement as void and null. Perhaps, it's a better way to say, Sweden did her best to balance between the Axis' and the Allies' claims, demands and while doing so, she broke her neutrality status. In the early phase of the WWII, Sweden even changed from neutral to non-belligerent considering the Winter War while aiding in multiple ways Finland, like sending 8 000- 10 000 Swedish volunteers to fight in the war.
As the Winter War ended, the Swedish participation also quickly was forgotten, while the global point of interest shifted elsewhere. Still, it didn't take much time, the Swedish neutrality was put in a real test in 1941. 'Midsommarkrisen' - 'Midsummer crisis' was a Swedish event at the beginning of the Operation Barbarossa. Germany demanded transit rights for German forces through Sweden from Norway to Finland during the Operation Barbarossa and the Continuation War. Sweden accepted for one German infantry division. While Germany was still pushing pressure, Sweden rejected any further concession and the German wishes to have Sweden joining the Axis. Sweden - however - carried on sending voluntary forces to Finland during the Continuation War and encouraged the Finns to wage war to weaken the Soviet Union for the Nordic benefit.
This short list is probably actually longer, but I gather some things, which, in my opinion are signs Sweden not being a neutral country during the WWII
- Sweden changing her status from neutral to non-belligerent during the Winter War
- Sweden sending volunteers for the Finnish Winter- and the Continuation Wars
- Midsummer crisis
- Trading with the Allies and the Axis powers
- For European recover, Sweden takes the Marshall Plan, while Finland doesn't