ORIGINAL: yvesp
You're overextending. You cannot be offensive in China (to the extent of destroying the commies), capture the NEI and India, and all at the same time protect Mandchuria. Not to mention that you'll also need troops to garrison the Pacific unless you want the US to easily seize them in a short time.
A smart Russian would take the opportunity to seize Mandchuria and its resources: This has no cost in terms of US entry (it is more than offset by your offensive stance), and you'll find yourself in a likely difficult situation.
Maybe you'll prove me wrong ?
Well I won't prove you wrong by any brilliant strategic moves on my part. But I will let you in on what's going on behind the scenes in my "alternate WW2 reality".
ORIGINAL: Centuur
Well well. A high risk, high gain game...
The USSR is the Allied power who should react on the Japanese. An invasion of Manchuria means the end of Japanese expansion and it comes cheap with all those extra US entry chits already drawn.
The Japanese can't fight the Soviets and China and still gain territory from the CW at the same time...
Alternate WW2 Reality
Stalin through his purges of the Red Army in the late 1930's has cemented total control over the Soviet Union and the blind following of the Red Army. Western estimates place the number of soldiers purged (i.e., executed) at 30,000 to 40,000. This includes 50% of the entire Red Army Officer's corps, 90% of their corps commanders and 3 of 5 of their Marshalls.
While Stalin is convinced that no credible threat inside the Soviet Union and, especially inside the Red Army, now exists to him, he is now worried that an extensional threat in the form of Nazi Germany is building to the Soviet Union and by extension to himself. He realizes that the severity of this extensional threat is greatly magnified by his purges of the Red Army. While he personally accepts the necessity of these purges, he knows that he now must take steps to rebuild the Red Army to the strength and competence necessary to stymie or even defeat the Nazi war machine if so necessary.
Stalin is under no illusions about the Nazi-Soviet non-aggression pact. It's not worth the paper it's written on. All he is looking for is to buy time, as much time as he can to strengthen the Red Army in his own image.
In Asia, Stalin not only sees what the Japanese are doing but has secretly negotiated an unofficial and very private non-aggression pact with them. He plans to give the Japanese a free hand in the Pacific and in Asia as long as they stay out of the Soviet Union. This free hand includes war against Mao and his communist. Though Stalin is not happy about this, he is a practical man and thus is willing to sacrifice the communist Chinese for the greater good of the Soviet Union. The greater good in Stalin's mind includes the eventual defeat of Nazi Germany and the incorporation of not only the rest of Poland but Germany and the Balkans into the Soviet Union. His closest advisers estimate that this will be possible in 5-years as long as the Soviet Union can stay out of a war with Nazi Germany for that time.
Now Stalin is a patient man when in comes to matters of conquest and absorption. Once Nazi Germany is dealt with, he, that is, the Soviet Union will be in position to take all of Manchuria and most (if not all) of China. But first, back to the his 5-year plan and the absorption of most of Europe into the Soviet Union. Stalin assumes that the French and British will be able to stalemate Germany in the west and tie them down for the needed 5-years. When ready, he will march in and save the the western allies and in the process gobble up most of Europe.
Now after all this is accomplished, Stalin will turn his attention to Asia. He plans once again to be the hero by ending a predicted war raging between the USA and Japan in the Pacific. Again he will be the hero, the savior, by marching in and defeating Japan in China. Of course, to do this he will need to push through and secure Manchuria.
Stalin sees endless opportunities in this new world war that's just ignited.
