personally i don't think so, i cant imagine how anyone could calculate that fighting on two fronts beat fighting on one front against the Germans. anyone got any real evidence one way or the other?
BTW, i think i am right in saying that around September 1941 the Germans had reached the high water mark of their military campaigns. Russians fighting them to a standstill in front of Moscow, and would roll them back following year, Rommel starting on the retreat in Africa. us supply kicking in everywhere for the allies.
the really dumb part of the Japanese strategy: they came in at the peak and it was downhill from there.
I'm pretty sure that CougarGA7 can cite chapter and verse (saving me the trouble of looking it up ;-) ), but I am certain that war with Japan was part of the joint American / British military strategy going back to at least 1940, if not before.
Early on it was decided that the war against Germany would receive first priority for US men & supplies, and that Japan would be kept on the "back burner" until after Hitler was defeated.
In the event, it turned out that the Pacific theater received a larger share of US resources that pre-war planning had imagined, because, to put it bluntly, enough Soviets were fighting and dying in the East to reduce the effort required to defeat Hitler in Western Europe.
Hence more resources available for the war on Japan.
As a person note: my Dad's 33rd Infantry Division originally trained for service in North Africa.
When that became unnecessary, the division was reassigned to the Pacific theater.
Just a small example of the Big Picture.
“... around September 1941 the Germans had reached the high water mark of their military campaigns.”
Actually, no. 1941 still has operation Typhoon on the front of AG Center, which will bring the German Army to the gates of Moscow, from which they’ll be driven in a Soviet counter-offensive starting December 6th. AG South will take [then lose] Rostov on the don in November.
In Africa, Rommel will be driven back to El Agheila in November, after Operation Crusader. BUT...
In January, 1942, Rommel will counterattack, and by August, he will be inside Egypt, at El Alamein. In Russia, the Germans will pinch off a Red Army offensive in May 1942, and riposte with the opening of Operation Blue, which will lead the German Army into the Caucasus, and the seizure of the Maikop oilfields, and to the banks of the Volga [at Stalingrad]. And Manstein will have seized the Crimea and Sevastapol.
So while the Germans were no longer capable [after 1941] of offensive operations in the USSR across the entire front, the high water mark of German military operations is at least a year off.