After failing to defeat the Soviet Union with Operation Barbarossa in 1941, Adolf Hitler planned a new campaign for the summer of 1942 that was intended to achieve a decisive victory: Operation Blue (Case Blau). In this new campaign, Hitler directed that one army group (Heeresgruppe A) would advance to seize the Soviet oilfields in the Caucasus, while the other (Heeresgruppe B) pushed on to the Volga River.