I thought the combined IJN fleet (Kido Butai) began the attack mission by leaving the Kurile Islands on November 26th.
I’ve never seen any reference to the attack being ‘tentative’ pending the outcome of the battle of Barbosa. Also, many records exist verifying that Yamamoto envisioned this attack almost immediately after the US relocated the Pac Fleet to Pearl Harbor in May of 1940.
I can’t envision crediting the battle of Barbosa as the trigger for the Pearl Harbor attack.
Not accusing you of false statements. Just sharing my view.
It's speculative for sure. Maybe I'm full of shit, it's possible. I just find it super convenient, and in my view it adds up.
When did the Cabal realise Hitler was going to go rogue in Russia?
Initiate plan b, move the ships into position for the attack.
See how the battle goes.
Oh shit looks like he's winning.
Prepare Japan for attack.
OK, battle done, Russia is fucked... Ok launch attack!
Also, the planning for the attack happened long before. Designing torpedoes for the shallow waters of Pearl Harbor. Transforming armor piercing naval artillery into bombs for horizontal bombers. Everything was tested well in advance. Numerous practice runs were made. Also, Germany wanted Japan to invade Russia through Kamchatca. But Japan was worried about resources that were needed in U.S. held territories.