The US is only generally on the side of Japan when they don't take a leading role. Even with the remilitarization in mind though it feels pretty, uh, I dunno. They make it out that literally everyone hates them "damn Japs" when in my experience the Japanese are actually one of the most well-liked foreigners, anywhere, known mostly for anime, being polite, their great food, and being somewhat cold and distant, which is pretty damn good considering what people generally have to say about their Asian neighbours or the other world powers. It's just weird. Like, is it projection?>>27581>It's basically the same deal as why Hollywood shows are either set in the United States or are only nominally set in (say) India or the Mideast
Writers write what they know, and when they write things they don't know they tend to do so poorly. Fu Manchu and Ivan Ivanichy Ivanovich are only amusing so many times before they're revealed for the caricatures they really are, and most plots in any case have no real need of foreign-ness. If you're talking about the agony of getting jilted or the stress of the Big Job, it doesn't really matter where the actual story is set outside of cultural coloration, and audiences generally like seeing things through a familiar lens, not a completely foreign one.