Question: The German invasion began one week after the signing of what neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939?
Sentence (from "Invasion of Poland"): The German invasion began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact, while the Soviet invasion commenced on 17 September following the Molotov-Tōgō agreement that terminated the Russian and Japanese hostilities in the east on 16 September.
Relevant evidence: Yes