Political map of Russia & the former Soviet Union 22 October 1942 (Case Blue): On June 28, Germany launched its great offensive of 1942: Case Blue (Case Blue), an attack across southern Russia to seize the crucial Baku oil fields (Baku) in Soviet Azerbaijan. However, by October, the German advance had stalled. The focus now shifted to securing control of the flanking city of Stalingrad (Battle of Stalingrad).