You may be missing the forest for all those pesky trees in the way... ;-)
Remember, the October 1940 meeting was now Richardson's second with Roosevelt, both times for the same reason -- Richardson doesn't like having the Pacific Fleet exposed and vulnerable at Pearl Harbor.
Richardson is disturbed and angry about it -- it's not safe, he tells FDR.
The fleet is too weak to do any good, it can't even protect itself against attack, unless kept on high-alert.
Oh, that's no problem, replies Roosevelt.
If the Japanese attack the Dutch East Indies or Thailand, we won't go to war with them.
If they attack the Philippines, we would "probably" / maybe go to war.
But, if they make a really serious "mistake" then we would certainly be at war, says FDR.
So I'd say that serious "mistake" can only mean Pearl Harbor.
After all, it's the whole focus of the discussion -- it's why Richardson is there in the first place.
FDR's strategy here is totally obvious.
He cannot, he will not, take the United States into war until or unless we have been seriously attacked.
And Hitler's U-boats sinking a few US ships in the Atlantic just won't do the job.
It has to be a serious attack on a major facility.
Well, which facility?
The Philippines was "probably" / maybe a serious enough target.
But the best Japanese target, to ensure US entry into war was the very one that Richardson had traveled all the way to Washington, DC, to discuss with his president.
Of course, in no possible way could FDR tell the Japanese where to attack.
But already, at this time in 1940, Roosevelt is thinking: where is the best place for an attack on the US to insure we will go to war.
And here was his Pearl Harbor commander, looking him in the eyes saying Pearl Harbor was too vulnerable and he couldn't be party to it.
So Richardson must obviously be replaced by someone less, well, understanding.
So, consider this question: is there any record of Richardson's replacement, Admiral Kimmel, having ever met with FDR to discuss such strategic matters?
Answer: no, Kimmel was a patsy, neither told nor expected to ask about grand strategy.
Next there's this issue about the meetings with Richardson and FDR. The supposition that Richardson concern was that the American fleet would get attacked paints a narrow picture of the entire argument. From Richardson's own testimony in the Joint Committee on the Investigation of the Pearl Harbor Attack conducted in 1946.
When asked about why he was against the fleet being at Pearl Harbor:
"My objections for remaining there were, primarily, that you only had one port, secure port, and very crowded, no recreation facilities for the men, a long distance from Pearl Harbor to the city of Honolulu, inadequate transportation inadequate airfields."A carrier cannot conduct all training for her planes from the carrier deck. In order to launch her planes she must be underway at substantial speed, using up large amounts of fuel. So that wherever carriers are training their squadrons there must be flying fields available, so that while the ship herself is undergoing overhaul, or repair, or upkeep, the planes may conduct training, flying from the flying fields
"There were inadequate and restricted areas for anchorages of the fleet; to take them in and out of Pearl Harbor wasted time.
"Another reason, which was a substantial one: Americans are perfectly willing to go anywhere, stay anywhere, do anything when there is a job to be done and they can see the reason for their being there, but to keep the fleet, during what the men considered normal peacetimes, away from the coast and away from their families, away from recreation, rendered it difficult to maintain a high state of morale that is essential to successful training.
"For those reasons, and because I believed that the fleet could be better prepared for war on a normal basis on the west coast, I wanted to return to the west coast."
Now concerning the October meeting itself:
Richardson did not like that the reason for basing the fleet at Pearl were for political and not military reasons. FDR in this meeting told him it was to serve as a deterrence to Japan in which Richardson did not think it would work:
"I stated that in my opinion the presence of the fleet in Hawaii might influence a civilian political government, but that Japan had a military government which knew that the fleet was undermanned, unprepared for war, and had no training or auxiliary ships without which it could not undertake active operations. Therefore, the presence of the Fleet in Hawaii could not exercise a restraining influence on Japanese action. I further stated we were more likely to make the Japanese feel that we meant business if a train were assembled and the fleet returned to the Pacific coast, the complements filled, the ships docked, and fully supplied with ammunition, provisions, stores, and fuel, and then stripped for war operations."
So it wasn't as much the fact that Richardson felt the fleet was unsafe at Pearl, though many commanders did broach the question, but it was more a point that it would not be able to prepare for war as well in this remote area as it could back on the West Coast. In a letter that Stark sent Richardson on November 22nd 1940, Stark asked Richardson about the safety of the fleet at Pearl from Japanese attack in which Richardson responded on the 28th in a note that said: "*This feature of the problem does not give me a great deal of concern and, I think, can be easily provided for.*"
In all of Richardson's testimony, never does he make the assertion that FDR felt the Japanese would strike Pearl Harbor and that FDR would let it happen. And those who fixate on the potential of attack as the sole source of the argument are really suffering from tunnel vision.
And it still doesn't offer any evidence that FDR knew Pearl Harbor would be attacked and just let it happen.