> Because foreigners are even less accountable to Americans and even less interested in their well being than any domestic group?

That is not necessarily true. The Hitlers and Putins of the world will happily sacrifice their own citizenry and their country's future for more power in the moment. It's entirely possible for some foreigners to hold more goodwill towards a country than its own leadership.

> I mean, to be a little outlandish: if there was a conflict, and some foreign adversary could transmit a mind virus to Americans that would cause them to go on murderous rampages and kill everyone, they'd probably do it. It'd be an instant win, and there'd be some sweet, sweet land to colonize afterwards.

Several countries are entirely capable of doing this with nukes.