Defence of the Reich
The Defence of the Reich was the strategic defensive aerial campaign fought by the Luftwaffe of Nazi Germany over German-occupied Europe and Germany during World War II against the Allied strategic bombing campaign. Its aim was to prevent the destruction of German civilians, military and civil industries by the Western Allies. The day and night air battles over Germany during the war involved thousands of aircraft, units and aerial engagements to counter the Allied bombing campaigns. The campaign was one of the longest in the history of aerial warfare and with the Battle of the Atlantic and the Allied naval blockade of Germany was the longest of the war. The Luftwaffe fighter force defended the airspace of German-occupied Europe against attack, first by the RAF Bomber Command and then against the RAF and United States Army Air Forces in the Combined Bomber Offensive.
In the early years, the Luftwaffe was able to inflict a string of defeats on Allied strategic air forces. In 1939, Bomber Command was forced to operate at night, due to the extent of losses of unescorted bombers flying in daylight. In 1943, the USAAF suffered several reverses in daylight and called off the offensive over Germany in October limiting their attacks to western Europe as they built up their force. During the war the British built up their bomber force, introducing better aircraft with navigational aids and tactics such as the bomber stream that enabled them to mount larger and larger attacks while remaining within an acceptable loss rate. In 1944 the USAAF introduced metal drop tanks for all American fighters including the newly arrived North American P-51D Mustang variant, which allowed fighter aircraft to escort USAAF bombers all the way to and from their targets. With a change of focus on destroying the German day fighter force, by the spring of 1944 the Eighth Air Force had achieved air supremacy over Western Europe, which was essential for the Allies so they could carry out the invasion of France. The strategic campaign against Germany eased as the Allies' Transport Plan focused their resources on isolating northern France in preparation for the invasion.
American strategic bombing raids in June and July 1944 seriously damaged 24 synthetic oil plants and 69 refineries, which halted 98 per cent of German aviation fuel plants and dropped monthly synthetic oil production to 51,000 tons. After these attacks, recovery efforts in the following month could only bring back 65 per cent of aviation fuel production temporarily. In the first quarter of 1944, Nazi Germany produced 546,000 tons of aviation fuel, with 503,000 tons coming from synthetic fuel by hydrogenation. Aviation fuel stock reserves dropped to 70 per cent in April 1944, to 370,000 tons in June 1944, and to 175,000 tons in November. The oil campaign of World War II led to chronic fuel shortages, severe curtailment of flying training and accelerated deterioration in pilot quality, eroding the Luftwaffes fighting capacity in the last months. By the end of the campaign, American forces claimed to have destroyed 35,783 enemy aircraft and the RAF claimed 21,622, for a total of 57,405 German aircraft claimed destroyed.
The USAAF dropped 1.46 million tons of bombs on Axis-occupied Europe while the RAF dropped 1.31 million tons, for a total of 2.77 million tons, of which 51.1 per cent was dropped on Germany. With the direct damage inflicted on German industry and air force, the Wehrmacht was forced to use millions of men, tens of thousands of guns and hundreds of millions of shells in a failed attempt to halt the Allied bomber offensive. The Luftwaffe's losses in this theater also sapped an enormous amount of Germany's overall war-making potential: aircraft accounted for some 40% of German military expenditures from 1942 to 1944.
From January 1942 to April 1943, the German arms industry grew by an average of 5.5 per cent per month but by summer 1943, the systematic attack against German industry by Allied bombers brought the increase in armaments production from May 1943 to March 1944 to a halt. At the ministerial meeting in January 1945, Albert Speer noted that, since the intensification of the bombing began, 35 per cent fewer tanks, 31 per cent fewer aircraft and 42 per cent fewer lorries were produced than planned because of the bombing. The German economy had to switch a vast amount of resources away from equipment for the fighting fronts and assign them instead to combat the bombing threat. The intensification of night bombing by the RAF and daylight attacks by the USAAF added to the destruction of a major part of German industries and cities, which caused the Nazi economy to collapse in the winter of 1944–45. By this time, the Allied armies had reached the German border and the strategic campaign became fused with the tactical battles over the front. The air campaign continued into April 1945, when the last strategic bombing missions were flown, and it ended upon the German unconditional surrender on 9 May.
German defensive strategy
The Luftwaffe lacked an effective air defence system early in the war. Allied daylight actions over German controlled territory were sparse in 1939–1940. The responsibility of the defence of German air space fell to the Luftgaukommandos, which controlled the anti-aircraft artillery, the civilian Aircraft Warning Service, and fighter forces assigned to air defence duties. The defences were directed by the Luftverteidigungskommando and its coordination and communication did not always work out smoothly in practice. The lack of common understanding between liaison officers from the AAA and flying branches plagued the strategic defensive aerial campaign throughout the war.Adolf Hitler, in particular, wanted the defence to rest on anti-aircraft guns as it gave the civilian population a "psychological crutch" no matter how ineffective the weapons. However, there were larger problems with the air defence system in the fall of 1939. LVZ West often drew forces away from participating in the Luftgaukommandos, which were assigned to protect specific objectives in its homeland defence. Had the Allies launched a large scale air offensive against the Ruhr region, it would have been particularly difficult to defend against Allied raids during that time, as the Luftgaukommandos would have lacked an effective force in interception of enemy aircraft. The air defences remained ineffective and unchallenged in the years 1939 to 1942, because Allied air forces were too weak to take advantage, which ensured that this danger remained hypothetical. Only seven Gruppen covered German air space, with the critical industries not well protected.
On 21 September 1939, Hans Jeschonnek, the Luftwaffes Chief of Staff, clarified the role of the day fighter force in the defence of German territory. Fighter units earmarked for specific defensive tasks would remain under local air-defence command. However, all other fighter units would be organised under one of several Luftflotten, which would prosecute the defence of German targets in a manner "linked directly with the strategic concept for the continued conduct of the air war". In other words, the Luftwaffe fighter force would act as both a defensive and offensive force, maintaining air superiority over enemy air space would prevent enemy attacks on German-held territory. This kind of strategy worked well at the front, but it soon became clear that a lack of training, experience and coordination between the Fliegerdivisions and the AAA arm, when dealing with strategic defensive operations, made the conduct of combined arms operations difficult.
Most of the air battles fought through May 1941 by the Luftwaffe on the Western Front were against the RAF's "Circus" raids and the occasional daylight raid into German air space. This was an unfortunate position since the Luftwaffe's strategy of focusing its striking power on one front started to unravel with the failure of Operation Barbarossa, the invasion of the Soviet Union. The "peripheral" strategy of the Luftwaffe, advocated by Jeschonnek, had been to deploy its fighter defences at the edges of Axis occupied territory, with little protecting the inner depths.