Perhaps a better question is, in what decades did the US start being a bully to others, including its own citizens.

It probably started with Latin American countries (CIA coups, Smedley Butler), vietnam, Iran (Shaw), Afghanistan (when the CIA radicalized them to fight the russians), etc. Ike warned of the MIC, and he was right. Now we're turning the lens inward, as the empire is totally insolvent.