
The U.S. was never isolationist and we absolutely were constantly embroiled foreign conflicts because believe it or not, Native American tribes are their own sovereign entities. We just ran out of room to extract resources on this continent so we moved on to the rest of the world. And why don’t you go ask Cuba and the Philippines just how isolationist we were in the early 20th century
They were never really that active even before that, but they certainly were running out of destiny to manifest (which we obviously shouldn’t continue). They weren’t completely isolationist but certainly much more by 1900. And fym “out of nowhere” bro it was after WWII when the geopolitical landscape had drastically changed and America was now one of the two most powerful countries in the world