The problem with that is that some of the plans referenced predate Japanese planning for the Pearl Harbor raid. Some of the Army planning dates back to the fall of France in June of 1940.
If you have been following these threads over the past few months you will see that the relations between Japan and the US, UK and The Netherlands have been swiftly deteriorating since the Japanese occupation of French Indo-China. This places Japanese controlled territory on three sides of the Philippines leaving South through the Dutch East Indies as the only “non-hostile” route from Hawaii to the PI.
Their position in French Indo-China is also a dagger pointed at Singapore and the DEI and is an openly hostile act towards all three Western powers in the region..
FDR does not “need” Pearl Harbor. the Japanese are clearly mobilizing for war, it is just of question of where and when.
Pearl Harbor was simply the opening act of a complex plan to seize a large portion of the Pacific basin.
I think DeaconBenjamin is saying (correct me if I’m wrong) that F.D.R. may have leaked the Rainbow 5 plan BECAUSE he knew Pearl Harbor was going to get attacked. This would be an example of Roosevelt realpolitik in which he knows that a shooting war is about to start so he wants to set the stage to entice Germany to come into the fray after the attack on Pearl.
The only problem with this is that it still would be better to allow your forces to defend against the attack so you would have as many of your assets still intact in the Pacific after the Pearl raid. This would have prompted a stronger message to Pearl about the imminence of an attack on the facility itself. As it was, the men at Pearl had sufficient information to make the right decision and did not, but they were operating under the assumption that the Japanese would attack first near its home waters (DEI, Singapore, Philippines).
It still all points to that while officials felt an attack on Pearl Harbor was possible, they felt an attack on the Philippines was probable and got tunnel vision as a result.