DrDeth, I’m sure you’ll forgive us if we accept all historical evidence over your dad’s opinion.
It’s also completely illogical even on its face. The Phillippines would have been a crucial base to control a huge Pacific region, but which could not easily be retaken. If they held out, the U.S. would have been in a far superior position from the get-go. Though more vulnerable, they also would have been an existential threat to Japanese sea lanes. And of course, as the Philippines were a territory that was in the process of being made independent, the American public would not necessarily be willing to go to war over it.
On the other hand, the Japanese couldn’t take or hold Hawaii for even a minute, but an attack there was a direct strike on integral American soil. Had Roosevelt known of the attacks in advance, he would have. Also, you know these communications are documented, right? The government would have had to blast this out in such a manner that a number of American officers would have known about it.
The U.S. government did have some inkling that the Japanese might attack, but radically underestimated the size and scale of the assault. (There was quite a bit of laziness and sloppy planning in the armed services at the time.) Additionally, the Japanese originally intended to deliver their declaration of war immediately before the attack, ensuring it was “honourable” but also giving no chance to respond. This didn’t quite happen and the communication arrived late, making it doubly insulting.