[codethief]

I think we were busy recovering from a war that we had started for 10-20 years or so. :)

I guess by that time it was hard to catch up. Also, many of our scientists had left for the US during the war.

[actionfromafar]

And "encouraged" to go to Soviet lands, too.

[flohofwoe]

More like hijacked:

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