Imperial Japan intended to honorably deliver their formal declaration of war to the US before beginning their attack on US ships in Pearl Harbor on 7 Dec 1041.

Japanese planes attacked on Sunday 7 December 1941, 0748 HOURS Hawaiian Time (HT) or 1248 HOURS in Washington DC (Eastern Time Zone).

"Due to bureaucratic delays, decoding issues, and last-minute translations, the final version of the note was not delivered to US Secretary of State Cordell Hull until after the attack had already begun (around 1400 HOURS Washington time, or 0800 HOURS on 6 December in Japan)."

The Japanese pilots took off and attacked the docked and unguarded US ships at Pearl Harbor without knowing the declaration of war was not received.

How are you, American Unity?

A Japanese admiral was against attacking the US, made famous by the line: "Now we have awakened a sleeping giant" in the film Tora! Tora! Tora!

After the Meiji Period, Japan sent Defense Attaches, spies, delegates all over the world to learn from the West.

Tokyo knew who was powerful and who wasn't.

The Japanese basically copied the UK's surprise attack on Italian ships at Taranto (1940).

Japan, like Italy's powerful OVRA, had an excellent espionage service which makes another book recommendation for you: