That reminds me of a war movie I've watched, when Josh Hartnett's character said "I think WWII has just started" during the attack on Pearl Harbor. (That line is historically inaccurate).
In reality, people would just consider it the "war" (referring to the European theater) or "Jap invasion of America" marking the US entry into the conflict (the term WWII was not coined yet until after).
There's another anachronism from that movie around 34 minutes in (during the scene where the nurses are on a transport ship heading for the hospital) as the movie is meant to be portray 1941: you can literally see the USS Arizona memorial in the background as pictured and circled below:

It's a nitpicky detail that made it on the final cut, since that wasn't built until 1962 (way after the war!).