They didn’t fight any NAZIs, that I know.
They were “neutral”.
- Sweden changed the diplomatic status from “neutral” to “non-bellingerent” when Finland was attacked by Stalin.
Sweden aided Finland with arms and other goods to a value more or less comparing to 50% of Finland's GDP of that time.
If Finland is attacked by a Communist dictator, Sweden will not remain passive. Furthermore, Sweden warned the Allies of Operation Barbarossa and traded with Britain during WWII just like we traded with the Germans and everyone else - in order to survive Hell.
Does this make my grandfathers Nazis? Britain and the US traded with Nazi Germany as well (examples are Bank of England and Standard Oil).