The reason why Adolf Hitler attacked Russia on June 22, 1941, was three-fold: 1) to secure a permanent source of oil supply, and 2) to eliminate the latent Soviet threat on Germany, which arose out of deep idelogical differences between the two nations; 3) Lebensraum (living space), a geopolitical decision to expand eastward to create more space for the growing German population. Having invaded Poland in 1939 and defeated the Low Countries and France the following year, the Third Reich needed more oil and raw materials to meet the increasing demands of German military machine and armament industry; demands the newly conquered Western European countries could not meet, and, by early 1941, Germany had already become dependant on huge imports from the Soviet Union and Eastern European countries. As a result, Hitler looked to the East. The ideological rift that existed between the two countries was clear to see; Germany was ruled by an extreme-right, nationalist government, known as the Third Reich, while Russia was brutally governed by an extreme-left, communist regime under Joseph Stalin, a psycopath and paranoid man.
Signed eight days before the Whermacht invasion of Poland, the Molotov-Ribbentrop Treaty, known as the “Non-Aggression Pact”, included a secret clause that allowed each signing country to establish spheres of influence, through which both Stalin and Hitler could secure and exert political and economic influence on neighboring countries. Thus, as it had been previously agreed on in the Molotov-Ribbentrop Pact, by late September 1939, the Soviet Union had completed the conquest of the eastern portion of Poland, to which Stalin would soon attach the Baltic States of Lithuania, Latvia, Estonia, and a portion of Finnish territory as spheres of influence and later declared as parts of the Soviet Union. However, the real threat to Germany oil supplies arose when the Red Army invaded the Romanian territory of Bessarabia and Bukovina, building up a strong military force in the area, threatening to invade the country. Since Rumania accounted for 65% of German oil imports, Adolf Hitler became real worried about this new developing situation. As he stepped up his plans for a sudden attack on the Soviet Union, he also envisioned to seize the Russian oil fields of the Caucasus. The attack on the Stalin-ruled Russia was code-named Operation Barbarossa, ending up in the Battle of Moscow, from November 1941 to January 1942, while the German invasion of the Caucasus steppes was called Operation Fall Blau, which led up to Battle of Stalingrad.
Hitler attacks the Soviet Union (footage)