If national socialists, or even just fascists (which is quite possible, and if you've read Sinclair Lewis, you'd think so too), ever managed to take over the world, I'd do my best to resist them.
I wouldn't try to fight them with guns, because I'd die right-out, and they would just label me as a terrorist and use it for propaganda purposes. Instead, I'd fight them with words. I'd do exactly what die Weisse Rose did, and print pamphlets against the regime. Yeah, I'd probably be caught and executed at some point, but at least I'd die a martyr's death rather than the death of a terrorist.