When I was a university student in the dark days of the Cold War, researchers made no distinction regarding the country of residence of scientific workers. That

When I was a university student in the dark days of the Cold War, researchers made no distinction regarding the country of residence of scientific workers. That went for researchers from communist countries during the Cold War as well as from various other "evil regimes" in the aftermath. The idea of banning people from the scientific community simply never came up.