Comment by FpUser

Not administration sympathizer but:

I think there are of course valid security concerns and this could be logical solution free of way more problematic issues of dealing on case by case basis.

On the other hand this will play more to people choosing some other country to advance their science aspiration and slowly but surely erode pool of talent for the US to help it stay dominant.

Practically the US have used people like Wernher von Braun on good scale and very sensitive areas and it worked just fine for the country. Qian Xuesen might of course have couple of words on the subject of course