Primary sources stress how disruptive it was to have aircraft, like fighter aircraft, just come over you and strafe stuff. The americans are still working on developing fighters that can compete with the japanese fighters. Five minutes after the war starts, they're running into these zeros everywhere. Usually things are least defensible from the air.
Japan's rising sun goes supernova and engulfs a huge area of Asia and the Pacific. A war without mercy begins to develop infusing the whole conflict with a savage vibe.