Anybody can do anything but don't pretend to not understand my point: the loyalty an American will have for this or that foreign adversary will trend to 0 and be much less than foreigners from those countries or regions. This is obvious.

Or do you think non-immigrants can't do these jobs? We certainly don't need to have other people than citizens already here and born here do these things.

The question was is it possible to protect. What I said is possible and would protect against the problem. It would be good for the country and American citizens in many ways including national security.

> the loyalty an American will have for this or that foreign adversary will trend to 0

Yeah. National loyalty is not the only motivating force why someone would leak something. The common reasons why someone becomes an insider treat is MICE: Money, Ideology, Compromise, and Ego. It is not specific to immigrants.

It doesn't have to be loyalty even, it could just be authoritarian leverage.