Well, what bugs me (and I’m sure it bugs Jacobsen) is that no one has ever discussed this stuff with him, and he has a dozen articles on it. Also, even though it’s old, the book “Pearl Harbor: Final Verdict” by Clausen and Lee revealed stuff NO ONE has ever addressed. Clausen had clearance for MAGIC-—something none of the congressional inquiries had, or, at least, could reveal. So witnesses were constantly lying or changing stories because they couldn’t reveal MAGIC. Clausen found, among other things, that Gen. Short reversed the “alert” codes at Pearl in July of 41 and never told Marshall or the War Dept. “1=high” and “3-low” became JUST THE OPPOSITE. So when Washington asked if Pearl was on level 1 alert, Short told them yes . . . meaning to him, the lowest level. But Washington thought it was on the highest level!
An interesting aspect to all this is looking at what difference it would had made even if they were on the proper alert in Hawaii. I did a study of the layout and number of assets that Short had at his disposal to protect Oahu and was pretty surprised by what I found.
Two of the primary flak positions on Oahu that were designated to protect the harbor itself only existed on paper. These were supposed to be the new 90mm flak guns of which none had been delivered to Hawaii by the time of the attack. There were only 82 3-inch guns on the island and twelve of those were in positions that never even saw a Japanese aircraft.
A more effective anti-aircraft weapon for the low level aircraft would have been the 37mm guns. These were being used before the U. S. adopted the 40mm Bofors. There was only 144 slated to be positioned in all of Hawaii, the bulk of which were to be on Oahu. Of those only 20 had been delivered. More interestingly though was that the ammunition for the 37mm guns did not arrive until December 5th, 1941. So the small number of crews for these guns would have had no time to get proficient with them.
Even .50 caliber machine guns were in short supply. The approved defensive plan called for 308, but they only had 109. Both Bloch and Short had sent communications calling for at least 500 of these to effectively defend the island if not more.
Finally, there are the air assets. The P-36s and P-49s on the island were not a match for even the Japanese torpedo bombers much less the Zero. Of the twelve P-40Cs and eighty-seven P-40Bs thirty five were playing the role of “hanger queen” and were not even in condition to fly.
I’m not big on going into “what-if” history, but I think if General Short had issued the proper alert which would have had gun prepped with ammo, and planes in the sky, the outcome would not have been significantly different.