https://en.wikipedia.org/wiki/Molotov%E2...ntrop_Pact
Stalin realized that the French and British could do nothing to stop Hitler from "settling the Polish problem". He therefore thought it wise to cut a deal with Hitler. He would not oppose German occupation of most of Poland if the USSR could have the eastern part. This was agreed to in a secret codicil to the German-Soviet Non-Aggression Pact. Without a guarantee that the Soviets wouldn't "come to Poland's aid" Hitler may not have attacked on Sept. 1, 1939.
Stalin realized that the French and British could do nothing to stop Hitler from "settling the Polish problem". He therefore thought it wise to cut a deal with Hitler. He would not oppose German occupation of most of Poland if the USSR could have the eastern part. This was agreed to in a secret codicil to the German-Soviet Non-Aggression Pact. Without a guarantee that the Soviets wouldn't "come to Poland's aid" Hitler may not have attacked on Sept. 1, 1939.
