The Combined Bomber Offensive (CBO) was an
Allied offensive of
strategic bombing
Strategic bombing is a systematically organized and executed military attack from the air which can utilize strategic bombers, long- or medium-range missiles, or nuclear-armed fighter-bomber aircraft to attack targets deemed vital to the enemy' ...
during
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
in Europe. The primary portion of the CBO was directed against
Luftwaffe
The Luftwaffe () was the aerial warfare, aerial-warfare branch of the before and during World War II. German Empire, Germany's military air arms during World War I, the of the Imperial German Army, Imperial Army and the of the Imperial Ge ...
targets which were the highest priority from June 1943 to 1 April 1944. The subsequent highest priority campaigns were against
V-weapon installations (June 1944) and
petroleum, oil, and lubrication (POL) plants (September 1944). Additional CBO targets included
railyards and other transportation targets, particularly prior to the
invasion of Normandy
Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful liberation of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 ( D-Day) with the ...
and, along with army equipment,
in the final stages of the war in Europe.
The British bombing campaign was chiefly waged by night by large numbers of
heavy bomber
Heavy bombers are bomber Fixed-wing aircraft, aircraft capable of delivering the largest payload of air-to-ground weaponry (usually Aerial bomb, bombs) and longest range (aeronautics), range (takeoff to landing) of their era. Archetypal heavy ...
s until the latter stages of the war when German fighter defences were so reduced that daylight bombing was possible without risking large losses. The US effort was by day – massed formations of bombers with escorting fighters. Together they made up a round-the-clock bombing effort except where weather conditions prevented operations.
The
Pointblank directive initiated the primary portion
[Emerson p. 4] of the Allied Combined Bomber Offensive intended to cripple or destroy the German aircraft fighter strength, thus drawing it away from frontline operations and ensuring it would not be an obstacle to the
invasion of Northwest Europe. The directive issued on 14 June 1943 ordered
RAF Bomber Command and the U.S.
Eighth Air Force to bomb specific targets such as aircraft factories; the order was confirmed at the
Quebec Conference, 1943
The First Quebec Conference, codenamed Quadrant, was a highly secret military conference held during World War II by the governments of the United Kingdom, Canada, and the United States. It took place in Quebec City on August 17–24, 1943, at bo ...
.
Up to that point the
Royal Air Force
The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...
and
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
had mostly been attacking German industry in their own way – the British by broad night attacks on industrial areas and the US in "precision attacks" on specific targets. The operational execution of the directive was left to the commanders of the forces and as such even after the directive the British continued in night attacks on the majority of the attacks on German fighter production.
Casablanca directive
Both the British and the US (through the
Air War Plans Division) had drawn up their plans for attacking the Axis powers.
The British
Ministry of Economic Warfare (MEW) published the ''Bombers' Baedeker'' in 1942 that identified the "bottleneck" German industries of oil, communications, and ball bearings; a second edition followed in 1944.
At the January 1943
Casablanca Conference
The Casablanca Conference (codenamed SYMBOL) or Anfa Conference was held in Casablanca, French Morocco, from January 14 to 24, 1943, to plan the Allies of World War II, Allied European strategy for the next phase of World War II. The main disc ...
the
Combined Chiefs of Staff agreed to conduct the "Bomber Offensive from the United Kingdom" and the British
Air Ministry
The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force and civil aviation that existed from 1918 to 1964. It was under the political authority of the ...
issued the
Casablanca directive on 4 February with the object of:
After initiating the preparation of a U.S. targeting plan on December 9, 1942; on March 24, 1943,
General "Hap" Arnold, the USAAF Commander requested target information from the British,
[:
] and the "Report of Committee of Operations Analysts" was submitted to Arnold on March 8, 1943 and then to the Eighth Air Force commander as well as the
British Air Ministry, the MEW and the
Royal Air Force (RAF) commander. The COA report recommended 18 operations during each three-month phase (12 in each phase were expected to be successful) against a total of 6 vulnerable target systems consisting of 76 specific targets. The six systems were 1) German submarine construction yards and bases, 2) German aircraft industry, 3) ball bearing manufacture, 4) oil production, 5) synthetic rubber and tires, and 6) military transport vehicle production. Using the COA report and information from the MEW, in April 1943 an Anglo-American committee (composed of British
Chiefs of Staff and the American
Joint Chiefs of Staff) under Lieutenant General
Ira C. Eaker; led by Brigadier General
Haywood S. Hansell, Jr.; and including Brig. Gen. Orvil A. Anderson completed a plan for the "Combined Bomber Offensive from the United Kingdom", which projected the US bomber strength for the four phases (944, 1,192, 1,746, & 2,702 bombers) through to 31 March 1944. Eaker added a summary and final changes (into the "Intermediate Objectives" section), such as:
CBO Plan
A committee under Eaker, led by Hansell and including Brig. Gen.
Orvil A. Anderson, drew up a plan for Combined Bomber Operations. Finished in April 1943, the plan recommended 18 operations during each three-month phase (12 in each phase were expected to be successful) against 76 specific targets. The plan also projected the US bomber strength for the four phases (944, 1,192, 1,746, and 2,702 bombers) through 31 March 1944.
Eaker's "Combined Bomber Offensive Plan" was "a document devised to help Arnold get more planes and men for the
8th Air Force" and not "designed to affect British operations in any substantive way." on October 9, 1943. (p. 465) -->p=206 While the CBO Plan was being developed, the British independently drew up a plan in April 1943 entitled "The Attack on the GAF" which identified German fighter strength as "the most formidable weapon...against our bomber offensive" and advocated attacks on airfields and aircraft factories, The document recommended attacks on 34 airfields that were within range of the Rhubarb and Circus operations. The plan identified ten towns as suitable for attack by high level daytime bombing followed by RAF night attacks and may have influenced target selection by the Eighth AF (and, later, the Ninth AF). The Combined Chiefs of Staff approved the "Eaker Plan" on May 19, 1943, and identified six specific "target systems" such as the German aircraft industry (including fighter strength):
:1. Intermediate objectives
::German fighter strength
:2. Primary objectives:
::German submarine yards and bases
::The remainder of the German aircraft industry
::Ball bearings
::Oil (contingent upon attacks against
Ploiești
Ploiești ( , , ), formerly spelled Ploești, is a Municipiu, city and county seat in Prahova County, Romania. Part of the historical region of Muntenia, it is located north of Bucharest.
The area of Ploiești is around , and it borders the Ble ...
)
:3. Secondary objectives:
::Synthetic rubber and tires
::Military motor transport vehicles
Pointblank directive (PBD)
On 14 June 1943, the Combined Chiefs of Staff issued the Pointblank directive which modified the February 1943 Casablanca directive.
Along with the single-engine fighters of the CBO plan,
the highest priority Pointblank targets were the fighter aircraft factories since the Western Allied invasion of France could not take place without fighter superiority. In August 1943, the
Quebec Conference upheld this change of priorities.
Among the factories listed were the
Regensburg
Regensburg (historically known in English as Ratisbon) is a city in eastern Bavaria, at the confluence of the rivers Danube, Naab and Regen (river), Regen, Danube's northernmost point. It is the capital of the Upper Palatinate subregion of the ...
Messerschmitt factory (which would be
attacked at high cost in August), the ''Schweinfurter Kugellagerwerke'' ball-bearing (
attacked in October and also causing heavy USAAF losses) and the ''
Wiener Neustädter'' ''Flugzeugwerke'' (WNF) which produced Bf 109 fighters.
Beginning of operations
The Combined Bomber Offensive began on 10 June 1943
during the British bombing campaign against German industry in the Ruhr area known as the "
Battle of the Ruhr". Pointblank operations against the "intermediate objective" began on 14 June,
and the "Effects of Bombing Offensive on German War Effort" (J.I.C. (43) 294) by the Joint Intelligence Subcommittee was issued 22 July 1943.
The Germans built large-scale night-time decoys like the
Krupp decoy site (German: Kruppsche Nachtscheinanlage) which was a German decoy-site of the
Krupp
Friedrich Krupp AG Hoesch-Krupp (formerly Fried. Krupp AG and Friedrich Krupp GmbH), trade name, trading as Krupp, was the largest company in Europe at the beginning of the 20th century as well as Germany's premier weapons manufacturer dur ...
steel works in
Essen
Essen () is the central and, after Dortmund, second-largest city of the Ruhr, the largest urban area in Germany. Its population of makes it the fourth-largest city of North Rhine-Westphalia after Cologne, Düsseldorf and Dortmund, as well as ...
. During World War II, it was designed to divert Allied
airstrike
An airstrike, air strike, or air raid is an offensive operation carried out by aircraft. Air strikes are delivered from aircraft such as blimps, balloons, fighter aircraft, attack aircraft, bombers, attack helicopters, and drones. The official d ...
s from the actual production site of the arms factory.
Losses during the first months of Pointblank operations and lower-than-planned U.S. bomber production resulted in
Chief of the Air Staff Sir Charles Portal complaining about the 3-month CBO delay at the
Cairo Conference
Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...
, where the British refused a U.S. request to place the CBO under a "single Allied strategic air commander," as they did not want to interfere with, nor be part of, a decision they deemed unwise and purely of American military origin. After Arnold submitted the October 9, 1943 "Plan to Assure the Most Effective Exploitation of the Combined Bomber Offensive" on October 22 the "Allied Joint Chiefs of Staff" signed orders to raid "the aircraft industries in the southern Germany and Austria regions".
July 1943 was the first time that the USAAF would coordinate a raid on the same location as the RAF. They were to fly two daylight missions against industrial targets (U-boat pens and yards) in Hamburg following the opening raid of the
RAF campaign against Hamburg. However fires started by the night's bombing obscured the targets and the USAAF " were not keen to follow immediately on the heels of RAF raids in the future because of the smoke problem".
In October 1943
Air Chief Marshal Arthur Harris, C-in-C of
RAF Bomber Command writing to his superior urged the British government to be honest to the public regarding the purpose of the bombing campaign and openly announce that:
On February 13, 1944, the CCS issued a new plan for the "Bomber Offensive", which no longer included German morale in the objective: "The subject of morale had been dropped and
he number of cities with targetsgave me a wide range of choice. ... the new instructions therefore made no difference" to RAF Bomber Command operations (Arthur Harris). The February 13 plan was given the code name ''Argument'', and after the weather became favorable on February 19, Argument operations were conducted during "
Big Week
Operation Argument, after the war dubbed Big Week, was a sequence of raids by the United States Army Air Forces and RAF Bomber Command from 20 to 25 February 1944, as part of the Combined Bomber Offensive against Nazi Germany. The objective o ...
" (February 20–25). Harris claimed the Argument plan was not "a reasonable operation of war", and the Air Staff had to order Harris to bomb the Pointblank targets at Schweinfurt.
In practice the USAAF bombers made large scale daylight attacks on factories involved in the production of fighter aircraft. The Luftwaffe was forced into defending against these raids, and its fighters were drawn into battle with the bombers and their escorts.
Pointblank operations

Following the heavy losses (about a quarter of the aircraft) of "Black Thursday" (14 October 1943), the USAAF discontinued strikes deep into Germany until an escort was introduced that could follow the bombers to and from their targets. In 1944, the USAAF bombers—now escorted by
Republic P-47 Thunderbolt
The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American company Republic Aviation from 1941 through 1945. It was a successful high-altitude fighter, and it also served as the foremost American fighter-bombe ...
s and
North American P-51 Mustangs—renewed their operation. Eaker gave the order to "Destroy the enemy air force wherever you find them, in the air, on the ground and in the factories."
Eaker was replaced at the start of 1944 as 8th Air Force commander by then-Major General
Jimmy Doolittle Doolittle's major influence on the European air war occurred in early 1944 when he changed USAAF policy which required escorting fighters to remain with the bombers at all times. With his permission, some of the American fighters on bomber escort missions would fly further ahead of the bombers'
combat box formations with the intention of "clearing the skies" of any
Luftwaffe
The Luftwaffe () was the aerial warfare, aerial-warfare branch of the before and during World War II. German Empire, Germany's military air arms during World War I, the of the Imperial German Army, Imperial Army and the of the Imperial Ge ...
fighter opposition heading towards the formations. This greater freedom for the fighters inflicted heavy losses on the less maneuverable ''Zerstörergeschwader'' ("destroyer wings") of twin-engined
heavy fighters and their replacement, single-engined ''Sturmgruppen'' of
heavily armed and armored Fw 190s, clearing each force of bomber destroyers from Germany's skies throughout early 1944. After the bombers had hit their targets, the USAAF fighters were then free to strafe German airfields and transport infrastructure when returning to base, contributing significantly to the achievement of air superiority by Allied air forces over Europe.
Big Week
Soon after Doolittle took command of the 8th Air Force, between February 20 and 25, 1944, as part of the Combined Bomber Offensive, the USAAF launched "Operation Argument", a series of missions against the
Third Reich
Nazi Germany, officially known as the German Reich and later the Greater German Reich, was the German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a totalitarian dictat ...
that became known as "Big Week". The ''Luftwaffe'' was lured into a decisive battle for
air superiority through launching massive attacks by the bombers of the USAAF, protected by squadrons of Republic P-47 Thunderbolts and North American P-51 Mustangs, on the German aircraft industry. In defeating the ''Luftwaffe'', the Allies achieved air superiority and the
invasion of Western Europe could proceed.
Battle of Berlin
The wording of both the Casablanca directive and the Pointblank directive allowed Harris sufficient leeway to continue the British campaign of night-time
Area Bombardment against German industrial cities which targeted both the factories and - indirectly through destruction of housing - the factory workers.
[
Between 18 November 1943 and 31 March 1944, RAF Bomber Command fought the Battle of Berlin, a campaign of 16 major raids on the German capital, interspersed with many other major and minor raids across Germany to reduce the predictability of the British operations. In these 16 raids the RAF destroyed around 4,500 acres (18 km2) of Berlin for the loss of 300 aircraft. Harris had planned to reduce most of the city to rubble, break German morale and so win the war. During the period of the battle of Berlin, the British lost 1,047 bombers across all its bombing operations in Europe with a further 1,682 aircraft damaged, culminating in the disastrous raid on ]Nuremberg
Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
on 30 March 1944. The campaign did not achieve its strategic objective, and coupled with the RAF's unsustainable losses (7–12% of aircraft committed to the large raids), the official British historians identified it as an operational defeat for the RAF.[Daniel Oakman ]
Wartime Magazine: The battle of Berlin
' on the Australian War Memorial
The Australian War Memorial (AWM) is a national war memorial, war museum, museum and archive dedicated to all Australians who died as a result of war, including peacekeeping duties. The AWM is located in Campbell, Australian Capital Territory, C ...
website At the end of Battle of Berlin, Harris was obliged to commit his heavy bombers to the Transport Plan attacks on lines of communications in France as part of the preparations for the Normandy Landings
The Normandy landings were the landing operations and associated airborne operations on 6 June 1944 of the Allies of World War II, Allied invasion of Normandy in Operation Overlord during the Second World War. Codenamed Operation Neptune and ...
and the RAF would not return to begin the systematic destruction of Germany until the last quarter of 1944.
Pointblank outcome
Operation Pointblank showed that Germany's aircraft and ball bearings plants were not very vulnerable to air attack. Its production of synthetic rubber, ammunition, nitrogen, and ethyl fluid was concentrated in fewer factories and would likely have been much more vulnerable. Despite bombing, "German single-engine fighter production ... for the first quarter of 1944 was 30% higher than for the third quarter of 1943, which we may take as a base figure. In the second quarter of 1944, it doubled; by the third quarter of 1944, it had tripled, in a year's time. In September 1944, monthly German single-engine fighter production reached its wartime peak – 3031 fighter aircraft. Total German single-engine fighter production for 1944 reached the amazing figure of 25,860 ME-109s and FW-190s" (William R. Emerson). Following Operation Pointblank, Germany dispersed works of its aircraft industry across 729 medium and very small plants (some in tunnels, caves, and mines).
However, Operation Pointblank did help to diminish the ''Luftwaffe''s threat against the Allies, and by the Normandy Landings, the ''Luftwaffe'' had only 80 operational aircraft on the North French Coast, which managed about 250 combat sorties[ against the 13,743 Allied sorties that day.
According to Charles Webster and Noble Frankland, Big Week and the subsequent attack on the aircraft industry reduced "the fighting capacity of the ''Luftwaffe''" through threatening the bombing of strategic targets and "leaving the German fighters with no alternative other than to defend them" but "the combat was primarily fought and certainly won" by the US long range fighters.
]
Overlord air plan
During the "winter campaign against the German aircraft industry ... January 11 February 22, 1944", review began on the initial air plan for the Overlord which omitted the requirement "to seek air superiority before the landings were attempted."[ ("letter" cited by Mets notes 49 & 50, pp. 190,383; "notes" cited by Mets note 89, pp. 201,385)] Instead, the plan was to bomb communications targets (primary) and rail yards and repair facilities (secondary). Air Marshal Trafford Leigh-Mallory, who would command the tactical element of the invasion air forces had been assigned the responsibility on June 26, 1943, for drafting the plan, and at the February 14, 1944, meeting regarding the Overlord air plan, he claimed German fighters would defend and be defeated during the attacks on rail yards, and if not, air superiority would instead be won over the D-Day beaches. Harris rebutted that even after the planned rail attacks, German rail traffic would be sufficient to supply invasion defenses; and Spaatz proposed attacks on industry in Germany to require fighters to be moved away from the Overlord beaches to defend the plants. Tedder concluded that a committee needed to study the pre-Overlord targeting, but when the committee met in March, no consensus was reached.
On March 25, 1944 Portal chaired a meeting of the generals and restated the Pointblank objective of air superiority was still the highest CBO priority. Although the "Joint Chiefs of Staff" had previously argued that it was impossible to impede German military rail traffic due to the large reserve capacity, for the secondary priority Portal identified that pre-invasion railyard attacks only needed to reduce traffic so tactical airpower could inhibit enemy defenses during the first 5 weeks of OVERLORD.[
(quoted by Mets, p. 208) ] Sir John Kennedy and Andrew Noble countered that the military fraction of rail traffic was so small that no amount of railyard bombing would significantly impact operations.[ (quoted by Mets, p. 208)] As endorsed on March 6 by the MEW and the U.S. Mission for Economic Affairs, Spaatz again proposed that "execution of the oil plan would force the enemy to reduce oil consumption ... and ... fighting power" during Overlord. Although "concerned that military transportation experts of the British Army had not been consulted" about the Transportation Plan, Eisenhower decided that "apart from the attack on the GAF erman Air Forcethe transportation plan was the only one which offered a reasonable chance of the air forces making an important contribution to the land battle during the first vital weeks of Overlord". Control of all air operations was transferred to Eisenhower on April 14 at noon.
However, after "very few German fighters rose to contest the early attacks on French rail yards" and the Ninth (tactical) AAF in England had dropped 33,000 tons of bombs through April on French railway targets, Churchill wrote to Roosevelt in May 1944 that he was not "convinced of the wisdom of this plan" Although Tedder's original Overlord air directive in mid-April listed no oil targets, Eisenhower permitted Spaatz to test that the Luftwaffe would defend oil targets more heavily. During the trial raids of May 12 and May 28, German fighters heavily defended the oil targets, and after the invasion had not begun during the good weather of May, Luftwaffe fighters in France were recalled to defend Reich industry.[Jablonski Vol IV p78] The German plan was to await the invasion and then, "on the cue words 'Threatening Danger West'," redeploy fighter strength back to unused French air bases when needed against the invasion. The last two Jagdgeschwader 26 Fw 190As, piloted by Josef Priller and his wingman Heinz Wodarczyk, that were to be recalled conducted two of the very sparse Luftwaffe day sorties over the Normandy beaches on D-day, and on June 7/8 the Luftwaffe began redeploying c. 600 aircraft to France for attacking the Normandy bridgehead.
Pointblank operations ended on the fifth day of the Invasion. and the highest priority of the Combined Bomber Offensive became operations against the German rocket weapons in June 1944 and the Oil Campaign in September. Tedder's proposal to keep oil targets as the highest priority and place "Germany's rail system in second priority" was approved by the CSTC on November 1. On April 12, 1945, Strategic Bombing Directive No. 4 ended the strategic bombing campaign in Europe.
See also
* Operation Crossbow
''Crossbow'' was the code name in World War II for Anglo-American operations against the German V-weapons, long range reprisal weapons (V-weapons) programme. The primary V-weapons were the V-1 flying bomb and V-2 rocket, which were launched agai ...
* Oil Campaign of World War II
* Transportation Plan
Notes
;Notes
;Citations
References
* (cited by Mets, p. 409):
: Kuter quotes an Air Ministry memorandum for the July 5 meeting. (cited by Mets note 60, pp. 269, 394: at a "staff meeting the British Chiefs of Staff ... 5 July 1944 ... Portal had tried to move Harris away from area bombing to join in the attacks on oil. ... the recommendation that emerged was a gigantic attack on Berlin")
: became the secondary priorities. (quoted by Mets note 23, pp. 260,393)
*
* Craven, Wesley Frank, and Cate, James Lea, editors (1983). ''The Army Air Forces In World War II'', Air Force Historical Studies Office, (Vol. 1).
:(1949)
''Volume Two – Europe: Torch to Pointblank: August 1942 – December 1943''
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{{World War II, state=expanded
World War II strategic bombing
Aerial operations and battles of World War II involving the United Kingdom
Aerial operations and battles of World War II involving the United States
Military history of France during World War II
Aerial operations and battles of World War II involving Germany
Aerial operations and battles of World War II involving Canada