Answer:
America!
Step-by-step explanation:
There was a huge debate when WWII was breaking out because isolationists believed the US had no good reason to get involved in a dispute between foreign nations. They wanted to continue making our country itself stronger rather than getting into a war.
After WWI, the US kept an isolationist policy reflected in their hesitance to get involved during WWII -- they didn't want to be involved in another world war. ... this wasn't how it played out (*cue to the US getting involved in WWII and the Cold War then following*)