Ok I know this idea has been done to death, but here is the idea for what ever reason the Soviets invade Poland in 1936 but the Poles put up a damn good fight a hold the Soviets in eastern Poland, well with a flood of western assistance for Poland combined with the incompetence of the Soviet miltary the Poles pull a rabit out of their hat and manage to throw the Soviets back across the border and in the process capture huge amounts of Soviet troops and equipment.
A peace treaty is signed with the borders remaining the same. So lets say the war last from early 1936 to mid 1937 and in this period both sides learn some valuable lessons, the question is what lessons do they learn and what are the knock off effects of a Polish victory against the Soviets?
Poland has learned some valuble lessons and his sitting on all the Western aid and captured Soviet weapons and the Soviets are licking their wounds and Stalin is looking for someone to blame and a way to fix the Soviet army.
What are the effects of said conflict?