why did Roosevelt and later Truman chose to trust Marshall's opinions and totally ignored the collective viewpoints of MacArthur, Leahy, King and Nimitz, the people who were fighting the Japanese in the Pacific all this while, close to Japan islands, up to date intelligence reports. the Navy people surely were the experts of the Pacific war situation rather than Marshall whom was thousands of miles away in Washington. According to Leahy, Marshall was bent on bringing in Soviet Russia into the Far East war. that implied many hidden agendas why Marshall stubbornly insisted on a land invasion of Japan from Yalta to Potsdam.
good question. nimitz would be one i would trust when it came to strategy for the methodical destruction of japan. macarthur would have been the one to carry it out on land as the main islands of japan are too big for the marines, which were under the u.s. navy. naturally, for a navy admiral such as nimitz, a land phase of the war was never a good idea. these two were theater commanders at the front, busy with theater strategy, campaign and battle planning. what they were missing out were global politics and strategic post-war initiatives that were already in motion.
marshall, having been the mastermind of all theaters, in fact shaping the direction of the whole war, including massive military logistics and industrialization at home (u.s. shipyards were building dozens of essex class carriers, montana class super battleships; aircraft factories were churning out hundreds of superfortresses, thousands of bombers and fighters; vehicle plants were producing tens of thousands of tanks, jeeps, halftracks, trucks), was the right hand man of fdr and was intimately involved with all strategic repositioning of the planet's face with the uk, ussr, and to a lesser degree, china.
since japan attacked pearl harbor and brought u.s. into the war, the subjugation, humiliation and occupation of japan belonged with the u.s. the ussr was given berlin and thereby the occupation of east germany. nationalist china under cks were asked if kmt forces could lend a hand in the occupation of japan, but cks declined the offer. occupation, and humiliation under occupation, were drivers in how the war should be concluded. occupation could not be achieved without unconditional surrender, as the japs would prefer to sue for peace short of conditions that would humiliate them. but the japs would never sue for peace or a conditional surrender without inflicting pain and untold damage to reach a better position for bargaining.
imo, it was that risk of untold damage to u.s. forces plus the risk of soviets grabbing real estate in the far east as quickly as possible (proven by soviet divisions barreling with ease thru' manchuria) that might force japan to surrender with terms to the soviets instead of the u.s., that marshall went along with the atomic option. the planning for operation downfall for a fullscale invasion was already in progress whether the atomic trigger was pulled or not. it was only prudent and methodical for all options to be exercised, in parallel at least in the prep phase. in the event both bombs failed to detonate or reach their ultimate effect, op downfall would be unleashed.
marshall was also intimate with both chinese warring factions, commies and nationalists alike. he was more wary of the soviets than communism in general. knowing the common enemy was japan after germany was defeated, he wanted both chinese factions to work in harmony and win land campaigns in china by destroying the jap army on the mainland before they could be re-deployed to fight on the home islands. he always had the belief that china was an important counter weight to the soviets. losing china to the soviets would be disastrous to u.s. post -war strategy as that would lead to confrontation and eventually to a new war, something the american public would find detestful and be tired of. and he was right. it led to the cold war and the korean war. he was more far-sighted, strategically-sound, and future-minded than either nimitz or macarthur could ever imagine within their limited sphere of command, influence and responsibility.
