The Japanese decision to attack Sydney Harbour appears to have been influenced by a belief that Warspite was still there. The battleship had already left, making the attack a compact example of operational decisions formed around outdated or mistaken intelligence. In June 1942, Warspite instead searched unsuccessfully for the Japanese auxiliary cruisers Aikoku Maru and Hōkoku Maru. She influenced enemy planning even while absent, then spent her own time on a fruitless commerce-warfare hunt.
Notable Point · 55:14-55:48
Mistaken intelligence puts Warspite behind a Sydney attack
Japan's mistaken belief that Warspite remained at Sydney helps explain the harbour attack, while the battleship was actually hunting auxiliary cruisers elsewhere.