bobtaftfan means John Creighton, the US Naval Observer in Singapore. The message didn't have anything to do with Pearl Harbor, but was him passing on info that someone had told him someone else (the Brooke-Popham mentioned in bobtaftfan's quote) had said regarding whether the British believed that the US would offer armed support if the British acted "to forestall Japs landing Isthmus of Kra [or] to take action in reply to Nips invasion any other part of Siam [or] if Dutch Indies are attacked".
Apparently in the mind of Pear Harbor conspiracists, Roosevelt knew the US was already at war with Japan due to the Japanese being about to attack the British and Dutch in the Western Pacific (which made the British and Dutch activate their war plans to prepare for attack which means the US should have activated its own war plans in support of the British and Dutch), but still deliberately didn't notify his own military (especially the forces at Pearl Harbor) to be ready and alert for combat with Japanese forces by December 7th.
In reality, as Brooke-Popham himself reported to the British chiefs of staff, the British were still trying to avoid actual war with Japan, and merely made ready to activate their war plans just in case they were needed, but not to actually go onto a war footing or consider that a state of war existed between them and Japan. Even in response to hearing about two Japanese convoys headed for Southeast Asia on December 6th, he said,
"Bearing in mind the policy of avoiding war with Japan if possible - a policy which had been reaffirmed by the Chief of Staff as recently as the 29th November and the situation in the United States with the Kurusu talks still going on in Washington, I decided I would not be justified in ordering 'Matador' [his
plan for the defense of Malaya against Japanese invasion] on this information...the main reason being that at least 24 hours start was required before the anticipated time of a Japanese landing and this was most likely to be unavailable, should the three ships seen turn out to be part of a Japanese expedition. Further, the conditions for reconnaissance were bad, on the information available there could be no certainty that the Japanese were about to open hostilities, and on more than one occasion the British Minister to Thailand had stressed the serious consequences that would ensue should we be the first to break Thai neutrality. It is pertinent to record that, until the Japanese had committed some definite act of hostility against the United States, the Dutch, or ourselves, permission had not been given to attack a Japanese expedition at sea."
In other words, Creighton's message was a telephone-game mangling of the actual British actions being taken, the British and Dutch did not consider themselves to be actually at war with Japan before Pearl Harbor and therefore the US was also not at war with Japan because of that, and Roosevelt did not hide the fact that the US was currently at war with
anyone on the morning of December 7th, 1941.
