<Li> Battle of Atlantic </Li> <P> The Phoney War (French: Drôle de guerre; German: Sitzkrieg) was an eight - month period at the start of World War II, during which there were no major military land operations on the Western Front . It began with the German invasion of Poland on September 1st 1939 and the declaration of war by the United Kingdom and France against Nazi Germany on 3 September 1939, and ended with the German attack on France and the Low Countries on 10 May 1940 . </P> <P> Even though Poland was overrun in about five weeks in the German Invasion of Poland beginning on 1 September 1939 and Soviet invasion beginning on 17 September 1939, the Western Allies did nothing . War had been declared by each side, but no Western power committed to launching a significant land offensive, notwithstanding the terms of the Anglo - Polish and Franco - Polish military alliances which obliged the United Kingdom and France to assist Poland . </P> <P> The quiet of the Phoney War was punctuated by a few Allied actions . In the Saar Offensive in September, the French attacked Germany with the intention of assisting Poland, but it fizzled out within days and they withdrew . In November, the Soviets attacked Finland in the Winter War, resulting in much debate in France and Britain about an offensive to help Finland, but the forces finally assembled for this campaign were delayed until it ended in March . The Allied discussions about a Scandinavian campaign caused concern in Germany and resulted in the German invasion of Denmark and Norway in April, and the Allied troops previously assembled for Finland were redirected to Norway instead . Fighting there continued until June when the Allies evacuated, ceding Norway to Germany in response to the German invasion of France . </P>

Why was the period between the winter of 1939 and the spring of 1940 called the phoney war