Exactly how many North Korean scientists are working in the U.S. right now?

Not a lot, but what is your point exactly? There are a lot of really Chinese scientists working in the US, and the ones who are postdocs and research scientists at NIST are apparently being pushed out at the end of this month. They’ve already been vetted for security concerns, so that justification is kind of thin.

How many Taiwanese, German, Indian, French, South Korean, etc scientists are working in the US? The ones working at NIST are facing being pushed out at the end of September.