Events on June 20 in history

The United States Army Air Corps is deprecated to being the American training and logistics section of what is known until 1947 as the United States Army Air Forces, just two days before Hitler's invasion of the Soviet Union.

Operation Barbarossa (German: Unternehmen Barbarossa) (Russian: ) was the invasion of the Soviet Union by Nazi Germany and most of its Axis allies, starting on Sunday, 22 June 1941, during World War II. The operation, code-named after Frederick Barbarossa ("red beard"), a 12th-century Holy Roman emperor and German king, put into action Nazi Germany's ideological goal of conquering the western Soviet Union to repopulate it with Germans. The German Generalplan Ost aimed to use some of the conquered people as forced labour for the Axis war effort while acquiring the oil reserves of the Caucasus as well as the agricultural resources of various Soviet territories. Their ultimate goal was to create more Lebensraum (living space) for Germany, and the eventual extermination of the indigenous Slavic peoples by mass deportation to Siberia, Germanisation, enslavement, and genocide.In the two years leading up to the invasion, Germany and the Soviet Union signed political and economic pacts for strategic purposes. Following the Soviet occupation of Bessarabia and Northern Bukovina, the German High Command began planning an invasion of the Soviet Union in July 1940 (under the codename Operation Otto). Over the course of the operation, over 3.8 million personnel of the Axis powersthe largest invasion force in the history of warfareinvaded the western Soviet Union along a 2,900-kilometer (1,800 mi) front, with 600,000 motor vehicles and over 600,000 horses for non-combat operations. The offensive marked a massive escalation of World War II, both geographically and in the formation of the Allied coalition including the Soviet Union.

The operation opened up the Eastern Front, in which more forces were committed than in any other theater of war in history. The area saw some of the world's largest battles, most horrific atrocities, and highest casualties (for Soviet and Axis forces alike), all of which influenced the course of World War II and the subsequent history of the 20th century. The German armies eventually captured some five million Soviet Red Army troops. The Nazis deliberately starved to death or otherwise killed 3.3 million Soviet prisoners of war, and millions of civilians, as the "Hunger Plan" worked to solve German food shortages and exterminate the Slavic population through starvation. Mass shootings and gassing operations, carried out by the Nazis or willing collaborators, murdered over a million Soviet Jews as part of the Holocaust.The failure of Operation Barbarossa reversed the fortunes of Nazi Germany. Operationally, German forces achieved significant victories and occupied some of the most important economic areas of the Soviet Union (mainly in Ukraine) and inflicted, as well as sustained, heavy casualties. Despite these early successes, the German offensive stalled in the Battle of Moscow at the end of 1941, and the subsequent Soviet winter counteroffensive pushed the Germans about 250 km (160 mi) back. The Germans had confidently expected a quick collapse of Soviet resistance as in Poland, but the Red Army absorbed the German Wehrmacht's strongest blows and bogged it down in a war of attrition for which the Germans were unprepared. The Wehrmacht's diminished forces could no longer attack along the entire Eastern Front, and subsequent operations to retake the initiative and drive deep into Soviet territorysuch as Case Blue in 1942 and Operation Citadel in 1943eventually failed, which resulted in the Wehrmacht's retreat and collapse.

The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical rift developed between more traditional ground-based army personnel and those who felt that aircraft were being underutilized and that air operations were being stifled for political reasons unrelated to their effectiveness. The USAAC was renamed from the earlier United States Army Air Service on 2 July 1926, and was part of the larger United States Army. The Air Corps became the United States Army Air Forces (USAAF) on 20 June 1941, giving it greater autonomy from the Army's middle-level command structure. During World War II, although not an administrative echelon, the Air Corps (AC) remained as one of the combat arms of the Army until 1947, when it was legally abolished by legislation establishing the Department of the Air Force.The Air Corps was renamed by the United States Congress largely as a compromise between the advocates of a separate air arm and those of the traditionalist Army high command who viewed the aviation arm as an auxiliary branch to support the ground forces. Although its members worked to promote the concept of air power and an autonomous air force in the years between the world wars, its primary purpose by Army policy remained support of ground forces rather than independent operations.

On 1 March 1935, still struggling with the issue of a separate air arm, the Army activated the General Headquarters Air Force for centralized control of aviation combat units within the continental United States, separate from but coordinate with the Air Corps. The separation of the Air Corps from control of its combat units caused problems of unity of command that became more acute as the Air Corps enlarged in preparation for World War II. This was resolved by the creation of the Army Air Forces (AAF), making both organizations subordinate to the new higher echelon.

On 20 June 1941, the Army Air Corps' existence as the primary air arm of the U.S. Army changed to that of solely being the training and logistics elements of the then-new United States Army Air Forces, which embraced the formerly-named General Headquarters Air Force under the new Air Force Combat Command organization for front-line combat operations; this new element, along with the Air Corps, comprised the USAAF.The Air Corps ceased to have an administrative structure after 9 March 1942, but as "the permanent statutory organization of the air arm, and the principal component of the Army Air Forces," the overwhelming majority of personnel assigned to the AAF were members of the Air Corps.