Sorry isolationism has never worked... We tried it in the 30’s and looked what happened..
Sorry, we're talking about two different types of isolation. I'm talking about isolating nations that mean us ill. You're talking about "isolationaism." Two different things. We absolutely isolated the USSR, didn't trade with them, had almost no business relations with them, and dealt with their strongest allies in a similar manner. Another description of that type isolation was "containment."
How's the USSR doing these days?