But by the time the Americans and Australians started fighting the Japanese, it was already a world war. Sometimes this meant fighting or starving or being bombed, other times it meant production for the war. You don't think of Argentina as being a World War II powerhouse, for instance, but they were vital to the Allies, supplying 40% of British meat during World War II. Thanks, Thought Bubble. So not to sound jingoistic, but the entry of the US into the war really did change everything, although I doubt the Nazis could have taken Russia regardless. No one conquers Russia in the wintertime, unless you are, wait for it, the Mongols. Okay, we're going to skip most of the big battles of 1942, like the Battle of Midway, which effectively ended Japan's chance of winning the war, and focus on the Battle of Stalingrad.