Earlier quoted context omitted.
What if the foreignerns don't want to spied up on? Or do they count for less?
What is the use of acting naive about foreign affairs, diplomacy, and statecraft? Are you really suggesting that your country's intelligence service doesn't attempt to do the same?
Targeting "all foreigners" destroys trust that foreigners have in the USA system for trade and diplomacy, lowering the impact of the state on both.