I don't believe the least bit that there are more than a few people in South Korea who believe that they are living 'in a way dictated by fears of the American empire'.

I say this as someone living in a region where the 'local neighborhood' also has its challenges in the form of a wannabe world power local authoritarian hegemon. Alliances, including the one with the US, are seen as paramount for security and long-term sovereignty. If that also fulfills some US strategic interests, so be it. The alternative is dreadful.