If he knew they were going to attack Pearl Harbor he would have boosted defense at the base and prayed the Japanese were not successful. Just releasing the intell to the public would have gotten us into the war if FDR wanted. An actual successful attack would have knocked us out of the war before we ever got started.
The original attack plan was to knock out the Oil Depot, the sub pens, the navy repair yard and of course the carriers. The Japanese briefly debated having an invasion force land after the initial attack and holding onto Hawaii. Ultimately they decided against that aspect of the attack. However, anyone considering what would happen with a Japanese attack on Pearl would have to consider this possibility: the complete loss of Hawaii as a base of operation. You are then trying to run a Pacific campaign from California. The Japanese failed to blow up the massive oil depot even though they had designed and armed many of their aircraftr with weapons designed to do just that. The repair yard and sub pens were for the most part untouched.
Just as a side thought, why do we seem to remember the attack at Pearl Harbor( a true act of terrorism) and yet the true terrorist attack on our mainland is just a passing thought and some words in passing( I’m speaking in reference to the media’s attention).
“An actual successful attack would have knocked us out of the war before we ever got started.”
It reminds me of a line of dialogue from the greatest Out of Control Bus movie of all time, “Speed,” when Reeves punches a screwdriver through the gas tank or something, and somebody says (paraphrasing), “What, you thought you needed more of a challenge?”
If FDR was Machiavellian, why would he make his path to more power so difficult? Forget how much power he had already, let’s say he wants to be King of America and all he needs is a war to put him over the top. Why allow so much damage at Pearl? It’s like stabbing yourself in the testicles before the 100-yard dash. Isn’t winning part of the evil scheme?
Brings to mind the supposed quote from Yamamoto: "Japan would never invade the United States. We would find a rifle behind every blade of grass."