Interesting indeed, they had some potent weaponry, albeit the most dangerously potent after Germany surrendered. Still reading through the wiki armoury link Jan... Certainly useful, I dare say the book "Finland's Decision" partially ties into it on the political side slightly.
I think Sweden was very ready and even more careful of being on any seen on any 'one' side; much like Switzerland was, even though most people in the EU some in the US are ignorant of the rules about Neutrality and what limits and benefits it grants such Nations.
And so far that's largely ignoring the military histories and rivalries between the Swedish Empire, Prussia/(Pomerania) and the Germanic/Baltic Leagues from post Roman up to the 18th Centuary.