By skyforbes American here, supporter of the armed forces, war/history enthusiast (as much as one can be enthusiastic about war in the sense), and therefore a connoisseur of war movies. Currently watching Hacksaw Ridge (2016) and there are a lot of scenes glorifying the killing of Japanese troops, for obvious reasons.
It got me thinking, I've never heard of or seen any films or TV shows with a flipped script, real or fictional. Obviously most American war movies will show glory from the victors (American revolution, WWI, WWII, Vietnam, various middle east conflicts but also fictional like either of the Red Dawn films. This extends to video games and non-war movies, like most Die Hard films feature Germans and Russians as villains. Even franchises like John Wick aren't necessarily nationality-driven, but based in NY, a number of bad guys are soviet.
I'm certain foreign films may have a film that takes place in say, Russia, and Americans are antagonists. Best I could think of is Letters from Iwo Jima (2006) but it's been like 15 years since I saw it, and don't actually remember it. Maybe, the James Cameron Avatar franchise since the Earth RDA forces seems/speak with American dialects/accents.