'Argument' was the Allied six-day air offensive by Lieutenant General Carl A. Spaatz’s US Strategic Air Forces in Europe (Major General James H. Doolittle’s 8^th AAF in the UK and Major General Nathan F. Twining’s 15^th AAF in Italy), Lieutenant General Lewis H. Brereton’s 9^th AAF in the UK and Air Chief Marshal Sir Arthur Harris’s RAF Bomber Command in the UK against German fighter strength and production (20/25 February 1944).

In this operation, generally known as the 'Big Week', Allied bombers attacked the major aircraft production centres in both Germany and German-occupied Europe, causing a good deal of disruption, and their escorting fighters were able to tackle the German fighters which took-off to challenge the US maximum daylight effort. The Allied offensive destroyed substantial numbers of German fighters, though the real importance of the battle lay not so much with the infliction of severe losses on the German air force, but with forcing the Germans to use irreplaceable fuel supplies and to suffer the loss of yet more experienced pilots at a time when their flying schools were wholly unable to make good such losses with adequately trained replacements.

Within the overall context of the European strategic bombing campaign as detailed in the 'Pointblank' directive, on 20 February the US Strategic Air Forces, the 9^th AAF and RAF Bomber Command started a series of missions against German air-related targets in the ground and in the air. The planners intended to lure the Luftwaffe into a decisive battle by launching massive attacks on the German aircraft industry, and by defeating the Luftwaffe, the Allies knew they would have air superiority for the planned 'Overlord' amphibious assault on the mainland of Europe.

Another consequence of 'Argument' was the Germans' decision to increase still further their dispersion of several industries, particularly aircraft and ball-bearing manufacturing, despite the financial cost and the further dislocation of production. Although this ultimately enabled the Germans to continue and indeed step up fighter airframe production, it also rendered the industry extremely vulnerable to another factor, namely systematic attacks on the transportation network on which dispersed production was reliant.

The week-long offensive also seriously eroded the morale and capability of the Luftwaffe. US air crews claimed more than 600 German fighters destroyed and thus achieved almost immediate air superiority, and the Luftwaffe never recovered from the loss of so high a proportion of its steadily diminishing pool of skilled fighter pilots. Thus it was compelled to abandon full-scale aerial opposition to the Allies' daylight bombing missions in favour of rationing resistance as and when the tactical circumstances and capabilities dictated. Therefore the Germans were forced, in effect, to concede air superiority over occupied Europe and Germany itself to the Allies. The 'Big Week' also bolstered the confidence of US strategic bombing crews. Until that time, Allied bombers had tended to avoid contact with the Luftwaffe wherever possible, but from this time onward the US planners confidently and deliberately used any method, and especially 'Ultra' intelligence, that would force the Luftwaffe into combat with growing numbers of North American P-51 Mustang single-engined fighters, which possessed the range capability to escort the bombers to and from distant targets.

This policy allowed the USAAF to consider attacks on Berlin, the German capital. Raiding the German capital, Allied leaders reasoned, would damage important industries and bring the Luftwaffe to battle. Thus, on 4 March the USSTAF launched the first of several attacks against Berlin, the fierce air battles which resulted causing heavy losses on each side. But while the Allies could make good their losses without appreciable delay, the Germans could not achieve this and therefore grew steadily weaker.

By the spring of 1944, the Allied strategic forces operating under the dictates of the 'Pointblank' directive had attacked U-boat construction yards, aircraft manufacturing factories, transportation systems and centres, and other industrial facilities but with only limited success. They had fought the Luftwaffe in the skies over Europe and, despite suffering severe losses, had never turned back.

When the combined bomber offensive officially ended on 1 April 1944, and control of the strategic air forces passed to General Dwight D. Eisenhower for support of 'Overlord', Allied airmen were well on the way to achieving air superiority over all of Europe and, while they continued strategic bombing, the USAAF and RAF turned their attention to the tactical air battle in support of 'Overlord'.

For 'Argument', the Allied planned to entice the Luftwaffe’s fighter arm into a decisive battle by launching major onslaughts on the German aircraft manufacturing industry, the object being to encompass a major defeat of the German fighter arm and thereby bring about the situation of Allied air superiority required for the successful implementation of 'Overlord'.

'Argument' was based largely on the daylight bombing capability of the US Army Air Forces, but was supported by the night bombing capability of Air Chief Marshal Sir Arthur Harris’s RAF Bomber Command, which operated against the same targets. Harris in fact resisted any contribution by his forces as he believed that this would divert them from the nocturnal area bombing offensive in which he had total belief, and it was only after receiving a direct order from Air Chief Marshal Sir Charles Portal, the Chief of the Air Staff, that Harris reluctantly complied. Air Marshal Sir Roderic Hill’s RAF Fighter Command also provided escorts for USAAF bomber formations.

During 1943 and into 1944 Brigadier General Newton Longfellow’s (from 1 July 1943 Major General Frederick Anderson’s and from 6 January 1944 Lieutenant General James H. Doolittle’s) 8^th AAF had grown steadily in size and capability under the pressure of combat, and had begun to launch attacks deeper into Germany. The USAAF believed that the defensive firepower of its Boeing B-17 Flying Fortress and Consolidated B-24 Liberator four-engined heavy bombers, typically 10 or more 0.5-in (12.7-mm) machine guns mostly in power-operated turrets, would allow them to defend themselves as long as they flew in tight box formations, which offered the opportunity for overlapping fields of fire as each bomber covered two or more companion bombers. Combat experience soon disabused the Americans of this belief, for with their greater speed and agility the German fighters were able to plunge through the bomber boxes and use their 20- and 30-mm cannon, firing explosive projectiles, to knock down large numbers of bombers. The gunners of the bombers claimed very considerable numbers of German fighters shot down, but these claims were significantly greater than the reality, and the rate of bomber losses was not sustainable.

This became apparent as the lessons of 'Juggler' (the first Schweinfurt and Regensburg mission on 17 August 1943) were digested: 230 bombers attacked the ball-bearing factories in Schweinfurt and another 146 the aircraft factories in Regensburg, in the process losing 60 of their number before returning to their bases, where another 87 had to be scrapped as they were beyond economic repair. The Germans admitted the loss of only 27 fighters. A second raid, on 14 October, was almost as costly: 291 aircraft were despatched, and of these 77 were lost. Neither attack inflicted decisive damage on its target factories, and the 8^th AAF was compelled to call a temporary halt in its programme of daylight missions into Germany as its bomber force was rebuilt.

The two missions were exhaustively studied by both the Americans and the Germans, the latter concluding that their current tactic of using heavily armed twin-engined bomber destroyers was working well. Over the winter of 1943/44 they continued this programme, adding to their numbers of heavy fighter and developing heavier weapons for all of their aircraft. They also pulled almost all of their fighter forces back into Germany, as the majority of their losses stemmed from fighter actions over forward areas. There seemed to be little merit in attacking the bombers with large numbers of US and British fighters in the area.

The Allied assessment of the two raids reached different conclusions, namely that bombers were unable to protect themselves adequately, as had earlier been believed, and thus that fighter escort had to be provided for the whole of any mission. Luckily for the UAAF, the right fighter for the task was available in the form of the P-51, which had started to arrive at English bases in swelling numbers and possessed all the attributes, especially in range, required of an escort fighter. Over the winter of 1943/44 the USAAF reorganised its fighter squadrons as the Mustang arrived in larger numbers, and as longer-range versions of its existing Lockheed P-38 Lightning twin-engined and Republic P-47 Thunderbolt single-engined fighters were developed.

As better flying conditions appeared early in 1944, the Americans and the Germans had largely completed their plans and looked forward to testing them in combat. Believing that it had the advantage in fighters, the USAAF planned missions that would force the Germans to respond. This was the genesis of 'Argument', which was based on a series of large attacks on German fighter factories. The American belief was that if the Germans chose not to respond they would risk losing the air war without firing a shot, and if they did respond they would meet superior fighters and suffer heavy losses.

In fact the Germans needed no provocation, for they were fully prepared to contest future raids with their newly upgraded forces. Unfortunately for the Germans, however, they had failed to appreciate adequately that the upgunning of their fighters had also increased weight and drag, thereby reducing their performance and rendering them easier targets for the new and unexpected Mustang.

The USAAF flew heavily escorted missions against airframe manufacturing and assembly plants and other targets in numerous German cities including Leipzig, Brunswick, Gotha, Regensburg, Schweinfurt, Augsburg, Stuttgart and Steyr, and in this six-day campaign the bombers of the 8^th AAF flew more than 3,000 sorties from England and those of Twining’s 15^th AAF more than 500 sorties from Italy. The 8^th and 15^th AAFs dropped about 10,000 tons of bombs.

During 'Argument' the 8^th AAF lost 97 B-17 and 40 B-24 bombers, with another 20 scrapped as a result of damage, and the 15^th AAF lost 90 aircraft. US fighter losses were 28. Although the losses were high in absolute terms, the numbers of bombers involved in the missions were nonetheless much greater than they had been up to this time, and the losses therefore represented a much smaller percentage of the attacking force: the earlier Schweinfurt missions had cost the force just less than 30% of its aircraft, but for 'Argument' it was less than 7%.

The US aircrews claimed more than 500 German fighters destroyed, though this represented, as usual, a massive over-claim. The German losses were greatest among their twin-engined Zerstörer units, among which those flying the Messerschmitt Bf 110 and Messerschmitt Me 410 twin-engined fighters were savaged. More worrying for the German fighter arm was the loss of 17% of its pilots.

Moreover, and in sharp contrast with the situation in the previous year, the US losses in both aircraft and crews were entirely replaceable as the industrial might and training programmes in the USA had accelerated rapidly, while the Germans were already over-burdened as a result of the war on the Eastern Front. In overall terms, the 'Big Week' cost the Allies 392 bombers (261 US and 131 British) as well as 33 US fighters, while the Germans had lost 355 fighters and, perhaps more importantly, almost 100 pilots killed and others wounded.

So although it was not in itself a fatal blow to Germany, the 'Argument' offensive was nevertheless a matter of extreme concern for the Germans as it could be seen only as a portent of greater blows to come. The damage to the German aircraft industry was fairly limited, and during 1944 the industry reached its maximum production capabilities. However, the lack of skilled pilots, as a result of the attrition inevitable in Germany’s involvement in the air over three fronts, was the single factor most responsible for the degradation of the German fighter arm’s overall capabilities. As an immediate consequence, therefore, the Luftwaffe was compelled to abandon its hitherto-standard tactic of maximum defensive effort against daylight bombing missions and instead switch to hit and run interceptions.

So while the German fighter arm still remained formidable and proved itself capable of striking major blows at the bombers, it was clear that the initiative in the air had passed to the Allies, who were now in the position to undertake a steady increase in their air superiority.

'Argument' also revealed major failings in the German aerial armoury, most notably that the fighter types the fighter arm believed to be its best anti-bomber weapons, namely the twin-engined Zerstörer designs, of which the Me 210 was the most modern, were extremely vulnerable to Allied fighters. Such fighters were therefore taken out of daylight service over North-West Europe, leaving the anti-bomber burden to be carried by single-engined designs offering higher performance and agility than the twin-engined types.

The Germans also reconsidered their tactics in the light of the effective escort that the Americans were able to provide for their bombers: from this time on, German fighters formed up ahead of the bombers, made a single head-on pass through the stream, and then departed. This revised tactics targeted the bombers' most vulnerable but at the same time least-defended aspect, and offered the escorting fighters the minimum time in which to react.

The results of 'Argument' also boosted the confidence of US bomber crews. Up to this time the US day bombers had sought to avoid contact with German fighters, but from this time onward the USAAF used every tactic it could conceive to draw the German fighters into combat, confident in the ability of their bombers (with added forward-firing guns) and escort fighters to break though the German defences, at an advantageous kill/loss ratio, bomb their targets and fight their way back to base.

A corollary of this revised thinking was the USAAF’s decision to attack Berlin, the German capital, in a raid which would force the German fighters into a major response. On 4 March, therefore, Spaatz’s US Strategic Air Force in Europe (formed on 22 February to co-ordinate the efforts of the 8^th and 15^th AAFs) launched the first of several attacks on Berlin. From England 730 bombers set out with an escort of 800 fighters, and in major running air battles there were heavy losses on each side: the Americans lost 69 B-17 bombers, but the Germans lost 160 aircraft.

The Americans could readily make good their losses while the Germans could not, but even so the new German tactics proved moderately effective. Kept in close contact with the bombers they were escorting, the US fighters could not chase down the attacking fighters before being forced to return to their charges. Doolittle responded by liberating the fighters from this close escort responsibility, thereby making it possible for them to roam away from the bomber streams and thereby search out and destroy the German fighters before the latter could close with the bombers. Though the change was unpopular with bomber crews, it immediately proved itself to be very effective.

When the combined bomber offensive officially ended on 1 April, as control of the strategic air forces passed to Eisenhower for tactical and operational use in the build-up to and implementation of 'Overlord', the Allies were well on the way to achieving total air superiority over all of Europe.