Those who suffered under these regimes tended to be the very best and the very brightest - the flower of their respective nations - so no wonder that Germany today has no arts or sciences scene worthy of its pre-1933 incarnation, and the post-Soviet Russian Federation continues to produce nothing noteworthy (or for that matter valuable) but natural gas and oil.
While I hesitate to wade into this thread, I do disagree with you on this final point. I've no dispute with what you say about the artists who suffered under these regimes, but I do have to observe that Soviet-era scientific research was considered of great importance in the west, and knowledge of German is thought to be almost indispensable in scientific research today, because of the quality and quantity of the material published in that language. THis may be a testimony to how well the country bounced back after 1945, rather than evidence that dictatorial regimes had encouraged it as well in self-interest, of course, but it is still true.
Post-Soviet Union, the quality of scientific publishing in the former Soviet area has certainly declined, though.
Well, you may very well be right about the sciences in Germany, Janet, I admit I'm not a sciences person. However, it seems to me the Germans no longer win as many Nobel Prizes as they used to in this field (having forced into exile most of their sterling geniuses, like Alfred Einstein, back in the 1930s). And as for the arts... well, Germany is not exactly stellar in this field. For example, I think most Americans would be hard-pressed to come up with more than a handful of German writers or artists who have made a name on the international scene in the last half-century or so. Certainly there is nothing comparable to the virtual renaissance of the arts - literature, painting, film, etc. - that took place under the Weimar government in the 1920s.
As for post-Soviet science, everybody who was anybody got out of Russia when they could, mainly in the early 1990s. The same thing happened in other academic fields. This is why Russian universities are so poor in quality today that they no longer even rank in international lists of the top universities around the world. Yes, that's right, not a single Russian university makes the list nowadays. Precisely because the most eminent professors fled that country as soon as the Soviet Union collapsed and they were able to get out. As one of my Russian literature professors told me, "I didn't want to leave. I love my country. But I had to be practical and think of my child's welfare."