The road would be long and hard, and massive preparations were still needed to win victory in the east. The issue was not in doubt, nor need the demands from the pacific bear too heavily on the great effort the united states was preparing to exert in europe. From war perspective, and over all war perspective, the reason people care about this is it flips the initiative. I changes what the japanese can do. And once the grinding part starts, that's when the fragility of things like the axis economies and resource base and population size and industrial capability are exposed.