Japanese get their idea of Eastern European sorry, Central European people from you. From your Hollywood. For them that area of the wold is just an exotic land, a terra incognita they can fill with any sort of characters and locations to their hearts content, because they don't know and don't care much about it. So most often Eastern Europeans are just side characters, following the same tropes and stereotypes implanted by the leading global mass culture.

 

Meanwhile their sentiment towards Americans is really personal and complicated. A whole roll of nation-wide complexes at work here. So if Russians would be just "low-level" mooks, like faceless enemy soldiers, an American villain would embody both a desire (to be him) and hatred (because he's "better"). And of course, the 90% of this sentiment revolves around the nuclear bombings, traces of which sentiment you can see in a majority of warfare-related animes and beyond ("Godzilla" franchise comes to mind, for example).

 

https://apjjf.org/-Matthew-Penney/3116/article.html