1 Feb 1939 Jahr - AUGUST 23- Soviet Union signs Non-Aggression Pact with Germany AUGUST 25 – Britain and Poland sign Mutual Assistance Treaty SEPTEMBER 1- Nazis invades Poland SEPTEMBER 3 – Britain, France / Austria / New Zealand declare war on Germany SEPTEMBER 4 – British Royal Air Force attacks the German navy SEPTEMBER 5 – United States proclaims neutrality SEPTEMBER 10 – Canada declares war on Germany; Battle on Atlantic begins SEPTEMBER 17