In your opinion, why was it necessary for the United States to embrace the role of an active superpower after the bombing of Japan?

In your opinion, why was it necessary for the United States to embrace the role of an active superpower after the bombing of Japan; in other words, why do you think the United States could not go back to being an isolationist power after World War II?

Your journal entry must be at least 200 words. No references or citations are necessary.