I agree long range of Japanese a/c, especially the shocking (to the Allies) reach of landbased A6M’s early in the war, was mainly a matter of the relative weighting of design characteristics with approx the same technologies used in the West. Nothing was particularly revolutionary technically about the planes or technology in them, although the West had assumed it would be inferior and it wasn’t. Also the sort of long range flying techniques experimentation and training done in the USAAF in mid war, as mentioned for P-38’s, was done in the Japanese Naval Air Force *before* the war.

Before the Pacific War that is. One big institutional impetus toward long range design requirements and training in the JNAF was their experience in China. They, rather than the Japanese Army, had the main force of “heavy” (would later be considered mediums by WWII stds, Type 96 Land Attack Plane, ‘Nell’) bombers. They did well when escorted by their own fighters, which could dominate the intercepting Chinese (sometimes Soviet piloted) fighter opposition in general. But when unescorted raids were tried early on, or when the key Chinese political/strategic targets were withdrawn into the hinterlands outside the range of Japanese fighters from coastal Chinese airfields, those ops often proved costly. Drop tanks on their A5M’s (Type 96 Fighter, ‘Claude’ in WWII) were a partial solution, but even a small number of A6M1’s sent there for operational evaluation, in 1940, turned the whole situation around (in raids against Chongqing where the Nationalists had move their capital). IOW the Japanese Navy had already gone through some of the lessons the USAAF learned in Europe and Pacific about the key value of long range fighters in supporting bomber operations, prior to 1941.

Joe