Hitler is therefore assassinated in the resulting power struggle in Berlin, and the coalition that emerges throws its lot in with Stalin.
Given the vehement anti-communism amongst all the anti-Nazis groups with any shot at power, the last thing they'd do is try to throw in with Stalin.
I love how most these proposals either require the Americans to drink lead paint and either A: ignore their pre-war plans entirely or B: be so fricking blind to the intentions of the Japanese that one would think the US is fighting a complete unknown rather than a competitor for control of the Pacific she has been facing for over 30 years or C: Requires Japanese omnipotence or D: the US backing the Japanese to fight the Soviets because reasons
Pretty much. Mind you, (A) isn't inconceivable like the others are. Although the Navy planners had clearly identified that a dash to base out of the Philippines would be suicidal, MacArthur had convinced the
Army otherwise and it is possible that the Army screaming for help to Washington long and loud enough could have led to the Navy being arm twisted into making a very bad play. Even within the Navy, there were those who chafed at the restrictions against offensive operations and would have been willing to attempt something more ambitious if the opportunity arose. Additionally, if America had been forced to declare war on Japan, and Japan had then sat back and done
nothing (beyond conquering the Dutch and British possessions along with a blockade of the Phillipines), America's pre-war plan - to retreat back across the ocean to safety - might have come off as ridiculous and cowardly. If the US Army remained sitting securely in the Philippines there would definitely have been great pressure to move the fleet forward to Manila and try to take the fight to Japan directly
now, not in two or three years when the fleet was fully ready.
So the Navy planners definitely identified the course of action that could lead them to their doom, but they could have been overruled had events conspired against them. Of course, not attacking the Philippines would have taken balls of steel on the part of the Japanese. It would have been a very gutsy play for them to leave seemingly so obvious a dagger aimed at the throat of their shipping lanes. In fact America actually had very few means to actually attack those sea lanes in 1941, nor would it have been able to improve the situation much in 1942... but the Japanese didn't know that and weren't inclined to think in that manner (using the Phillipines and even the homeland as bait to lure in the enemy) in any event.