This may, or may not, be related to my timeline.
Suppose the Japanese and soviets do not sign a non agression pact and a great scale conflict starts in 1940 over Manchuria and Mongolia. Is there any way for the japanese to win or at least force a favourable peace before, say, 1942?
EDIT: I think the Soviets still have a great advantage, but let's assume that the purgues have been worse than in OTL and that their tank research is not as advanced and their tanks in 1940 still resemble more T-26 rather than T-34.