During the 1940s, the Azerbaijan SSR supplied much of the Soviet Union's gas and oil during the war with Nazi Germany and was thus a strategically important region. The German invasion of the Soviet Union in June 1941 reached the Greater Caucasus in July 1942, but the Germans never crossed into the territory of Azerbaijan. Many Azerbaijanis fought well in the ranks of the Soviet Army (about 600-800,000) and Azeri Major-General Azi Aslanov was awarded twice Hero of the Soviet Union. About 400,000 Azeris died in World War II. The Germans also made fruitless efforts to enlist the cooperation of emigre political figures, most notably Mammed Amin Rasulzade.