The new nation developed as a democratic republic amidst the interwar turmoil in Europe. According to the August 1939 Molotov–Ribbentrop Pact between the Soviet Union and Nazi Germany, Finland was placed in the Soviet Union's sphere of influence. Consequently, the Soviets attacked Finland on 30 November 1939 to begin the Winter War. Helsinki was bombed immediately after the war commenced, and then several additional times during the war. After an unfavorable peace agreement to end the war, Finland took the opportunity to become a "co-belligerent" with Nazi Germany in World War II, fighting a Continuation War against the Soviet Union only. This also resulted in multiple bombings of Helsinki from 1941 to 1944, with the most significant series being three massive raids in February 1944.