@Imperious:
Yes the key to do that would have been to invade the Soviet eastern territories before they were transfered. The reality of a japanese “northern” solution was often discounded due to the huge defeat they faced in the border clash with the Soviets in 1939. Its hard to go against experience. My feeling is Stalin could have ignored or buffered this huge area with a few troops playing for time until a decisive outcome could have been obtained against Germany. The japanese didnt posess enough troops at any point to even push even 500 miles into Soviet Territory. They had to commit too many in China in a war that could not have been decided for even another 10 years. Remember they fought them since 1931 with no decisive result.
The key was to keep bagging Stalins armies using proven tactics. But with the strategic outlook of true mobile army having the ability to retreat and reform for counterattacks once the Soviet offensive lost steam. This elastic approach was what Manstein favored, while Hitler kept his old WW1 ideas intact. Hitler allowing his generals to fight the war would have brought victory. That along with the extra month of time.
Yeah, that was the other thing.
He acquired all of Europe through a mobile army, then hunkered down in the worst place in the world at the worst time.