Why it's Bullshit:
Because it's like thinking that while many X-Men contributed in their own special way, defeating Magneto really came down to Iceman.
There are two radically different histories of WW II, the one that was actually fought, and the one where the US kicked everyone's assess. Guess which one Cold War-era classrooms were allowed to teach? Here's a hint: It's the same one Hollywood chose to film.
World War II wasn't just a clever name. It was a global conflict that included epic acts of heroism by non-Americans like the storming of Madagascar, the Battle of Westerplatte, the Battle of Moscow, the Battle of Kursk, the epically badass Kokoda Track, the pilots of the Polish Underground State, the details of El Alamein or the HMS Bulldog. Of course, Americans never hear about any of those unless, as in the case of the classic submarine film U 571, the characters are just straight up switched to Americans. To quote George S. Patton: "Americans love a winner," which you know because you saw Patton, the film that portrayed Field Marshal Bernard "Rommel-killer" Montgomery like a buffoon simply because he was British.