Some point to this leak as evidence that FDR knew of the Pearl Harbor attack beforehand. Not the only evidence, just one element.
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.