> 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.

I would argue the word loyalty can encompass external pressures like that or internal affinity, ethnic tribalism and everything in between but yes, agreed.