Nagumo initially believed no American carriers were nearby, so Midway's continued resistance made another land attack seem necessary. That led him to replace anti-ship weapons with land-attack weapons. Reports of carriers then created a different problem: aircraft carrying land-attack bombs might reach the ships without inflicting the required damage. Returning to doctrine meant changing back to anti-ship weapons. The sequence was a serious command error, but the changing information and concern about weapon effectiveness explain how his training could lead him into it.
Notable Point · 53:54-55:04
Why Nagumo reversed the Midway aircraft armament
Changing reports pushed Nagumo from anti-ship weapons to land-attack weapons and back, exposing the danger of a deliberate doctrinal response during a rapidly changing battle.