You're talking about a country which prepared to biowarfare by dropping bacteria on its own civilian population (including San Francisco Bay Area[0]) to see what happens, without telling anyone. A country that has its own movie industry creating story after story of its military experimenting on people, to the point it's pretty much became a trope.

So no, I wouldn't be so sure this couldn't in principle happen in the US of A.

[0] - https://en.wikipedia.org/wiki/Operation_Sea-Spray