World War II: The Wehrmacht launched Case Blue, a strategic German offensive to capture oil fields in the south of the Soviet Union.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The Wehrmacht, were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer (army), the Kriegsmarine (navy) and the Luftwaffe. The designation "Wehrmacht" replaced the previously used term Reichswehr and was the manifestation of the Nazi regime's efforts to rearm Germany to a greater extent than the Treaty of Versailles permitted.

Case Blue was the Wehrmacht's plan for the 1942 strategic summer offensive in southern Russia between 28 June and 24 November 1942, during World War II. The objective was to capture the oil fields of Baku, Grozny and Maikop for two purposes: to enable the Germans to re-supply their low fuel stock and also to deny their use to the Soviet Union, thereby bringing about the complete collapse of the Soviet war effort.