I agree with you on punishment being commensurate with the crime being committed, since often even felonies in the billions of dollars has insignificant (if any) jail time and fines abysmal enough to be written off as merely the cost of doing business.. barely even a deterrent.

In terms of what happened post ww2, it was incredibly lenient because scientists, knowhow of the then new and innovative industrial processes developed at the time etc were so sought after that the lure of smuggling out chemists, engineers, physics guys, medical staff and researchers etc was so high it was irresistible. Thats how Wernher von Braun and large numbers of other german luminaries were ensconced in the US and kickstarted a number of industries like the advanced rocketry that resulted in the apollo project and ballistic missiles.

https://en.wikipedia.org/wiki/Operation_Paperclip