What was the most significant way in which imperialism affected Japan?

Imperialism pressured Japan to end its long period of isolation, especially after U.S. ships arrived and pushed Japan to open trade with foreign countries. Japan then engaged more with the outside world and modernized rapidly. This makes “Japan transitioned from being isolationist to being more open” the best answer; widespread adoption of Western food or Christianity was not the main effect.

AI-written and checked against the verified answer.