just half a year earlier, the Soviet union invaded Finland. Sweden sent one third of all its fighters, 144 pieces of artillery, 100 anti aircraft guns, 92 antitank weapons, 347 machine guns, 450 automatic rifles, 135000 rifles, 300000 grenades and 51 million cartridges to Finlands aid. And then 8000 volonteers to help Finland fight. The value of all this was more than the whole Finnish budget for a full year. And I mean the WHOLE budget, not just military spending.

Sweden was still in the process of training more troops and making more weapons when Germany attacked.

Had Sweden interfered with Germanys invasion of Denmark and Norway, Hitler would only have had to divert some of his troops and invade Sweden as well.

Had Sweden been invaded it would not have been able to house all the fleeing jews and other refugees from Norway and Denmark (50% and 99% of those countries jews respectively)

They would not have been able to listen in/spy on German communications and send information to the allies.

They would not have been able to train (and equip) Norwegian and Danish soldiers to assist in liberating their countries.

They would not have been able to ship back downed allied pilots that had emergency landed on swedish soil (bomber pilots mostly)

So in hindsight, "sitting on their hands" very likely did more good that foolishly get into a fight they couldnt have won.