Another thing to add, eastern Europe has comparable talent to western one and US, but a smaller budget.

That made eastern Europeans excel in sciences that needed a smaller budget (e.g. electro chemistry is much cheaper than photonics).

That's kind of what my a college physics professor from Korea told me (he emigrated to US in the 70s). They didn't have the all the fancy lab equipment but had paper and pencils so he got really good theoretical physics.