Ground Support versus Independent Operations
On i April 1944, with daylight air superiority secured, Operation Pointblank officially ended, and two weeks later Eisenhower assumed operational control of usstaf and raf Bomber Command. He retained the authority for the next five months. During that span he used the heavy bombers to disrupt transportation routes in northern France that the Germans could use to thwart the invasion, as well as to spur the drive of Allied armies across France after the landings. Winston Churchill initially balked over the prospect of substantial French casualties from the bombing, but relented when President Franklin Roosevelt stated an unwillingness to restrict any military action that “might militate against the success of ‘Overlord’ or cause additional loss of life to our Allied forces of invasion.”47 Approximately 4,750 French civilians died from the bombing of transportation lines before D-Day.48 To
Roosevelt and Churchill, those deaths were a small price to pay for a successful invasion that would shorten the war, especially since both leaders placed a higher premium on the lives of their own combatants than they did on the lives of civilians in occupied countries. Eisenhower sympathized with those views. On 6 June, he used B-17S to demolish twelve French towns and block roads in them that the Germans could use to move reinforcements to the invasion beachhead.49
American air commanders shared the progressive desire for rapid victory, but continued to maintain that independent bombing operations, rather than those devoted to ground support, offered the most inexpensive way to end the war quickly. Before departing England for his Mediterranean command, Eaker reviewed the Overlord plan and deemed the proposed use of B-17S and B-24S to support ground forces a mistake. “Heavy bombers are inefficient artillery,” he observed. “They have a more important assignment in the war effort which, incidentally, is more important to winning the battle on the beaches as well.”50 Arnold concurred in his response for “Eaker’s Eyes Only,” which Eaker received in the midst of his effort to prevent widespread use of Fifteenth Air Force bombers as “flying artillery” in the Italian campaign. “I have reason to fear that we will be dragged down to the level and outlook of the Ground Forces,” Arnold fumed. “Our airmen thoroughly know the capabilities of their Arm. They, and they alone, must control the operations of their Air Forces. It is, in my opinion, impossible for Ground Force officers to fully utilize vision and imagination in air action, since they are not well acquainted with air capabilities and limitations.”51
Spaatz despaired as well over the extensive use of his bomber force to support Overlord. In June, he scoffed at Eisenhower’s suggestion to have B-17S drop supplies to partisans in southern France, and also complained that British ground commanders “visualize the best use of our tremendous air potential as plowing up several square miles of terrain in front of the ground forces to obtain a few miles of advance!”52 Yet without a massive infusion of air power, Eisenhower’s invasion may well have stagnated in the Normandy hedgerows. For almost two months after D-Day, German troops and tanks prevented Allied armies from moving more than twenty miles inland from the invasion beaches. Operation “Cobra” made the difference. On 25 July, 1,495 American heavy bombers, 380 medium bombers, and 559 fighters blasted German positions near Saint-Lo.53 A follow-up attack by 200 medium bombers and five fighter groups the next morning broke the spirit of the German defenders, enabling American troops to pour into the gap and begin their drive to the German frontier.
Although he realized that air power had played a useful role in supporting Allied armies, Spaatz wanted to use his bombers independently, not as an auxiliary force, and in a way that would have a more decisive impact on Germany’s capability to fight—as well as highlight the distinctive contribution of strategic bombing to the Allied war effort.’4 He was of course familiar with awpd-i, AWPD-42, and Eaker’s proposal for the Combined Bomber Offensive, and all stressed oil as a vital component of Germany’s warmaking capacity. In January 1944, coa members had examined prospects for attacking oil production and refining centers. They rejected such raids because they estimated that the Germans would not feel effects from them for at least six months, too long a time to influence the battle for air superiority that Spaatz had to win by April.5S Once he had gained daylight control of the air, the desire to attack those targets resurfaced.
In late March, Spaatz argued that destroying Germany’s oil supply would provide the greatest support to the invasion by restricting enemy troop movements, but Eisenhower thought that attacks on transportation lines in northern France and Belgium would pay more immediate benefits.56 Still, in his initial bombing directive on 17 April, Eisenhower called for continued pressure on the Luftwaffe, and Spaatz reasoned that raids on oil facilities would compel the Luftwaffe to fight—and suffer attrition—much like the Big Week attacks on the aircraft industry. Spaatz pressed Eisenhower for limited attacks on oil—and even threatened resignation over the issue.57 Eisenhower relented, and gave him permission to use two good-weather days to attack synthetic oil facilities.
Spaatz knew that the plans for bombing Germany called for six months of concentrated attacks on key industries to produce telling results, yet he thought that he could inflict significant damage to the Nazi oil system with intermittent raids while the focus remained on supporting Overlord. He now possessed a vast force of more than three thousand heavy bombers, and Fifteenth Air Force provided the capability to attack key Balkan targets like Ploesti on a regular basis.58 In fact, Spaatz had already begun the assault on Ploesti under the guise of attacking the city’s rail yards to support the Russian advance in Romania—most of the bombing in three April raids caused “incidental” damage to Ploesti’s oil refineries.59 Despite the scattered nature of the oil system, comprising more than eighty facilities in Nazi-controlled Europe, the coa determined that certain targets were system linchpins—for instance, four Bergius synthetic oil plants produced half of Germany’s aviation fuel supply.60
Spaatz began the oil offensive with Eisenhower’s blessing on 12 May against the synthetic oil plants at Merseburg-Leuna, Zwickau, Bohlen, and other cities. More than eight hundred B-17S and B-24S attacked, with heavy fighter escort, and three hundred German fighters rose to intercept them. Eighth Air Force lost forty – six bombers and seven escorts, while the Luftwaffe lost sixty-five fighters.61 The enemy response following the raid showed that Spaatz’s bombers had indeed hit a vital part of the industrial web.
On 16 May, Spaatz received an Ultra intercept that the Germans had canceled the movement of nine flak batteries to France and sent them instead to synthetic oil plants, along with ten other flak batteries—some of which had defended aircraft factories.62 The Nazi Minister of Armaments, Albert Speer, recalled: “I shall never forget the date May 12. . . . On that day, the technological war was decided…. It meant the end of German armaments production.” A week after the attack Speer told Field Marshal Wilhelm Keitel, “The enemy has struck us at one of our weakest points. If they persist at it this time, we will no longer have any fuel production worth mentioning.”63
The results of the raids pleased Eisenhower, and he not only approved additional attacks on German oil targets for 28 and 29 May, but also permitted Spaatz to make oil usstaf’s top priority target on 8 June. Heavy bombers knocked out nine-tenths of aviation fuel production before Spaatz had to return his focus to invasion support on 22 June.64 For the next month, attacks on oil facilities fluctuated according to the needs of the ground offensive in France.
coa members spent much of June examining Germany’s oil system and revised their earlier estimate. This time they determined that oil was particularly vulnerable to bombing. Analysts concluded that the Germans could not easily hide or disperse their sprawling refineries and synthetic production facilities. In addition, the Germans possessed no excess refining capability. Ploesti was essential to the Nazi war effort, but other refineries in Germany, France, Belgium, and Hungary were also important. The coa identified twelve key refineries and five synthetic oil plants that, if destroyed in a single month, two months later would produce “a very serious curtailment in German military operations.” One analyst estimated that after three months, if other refineries remained at current production levels, “you will have immobilized the German economy. They will not be able to either fight or manufacture.”65
Such assessments intensified Spaatz’s desire to wreck German oil. As the air power demands in the Italian ground war began to subside, he dispatched Fifteenth Air Force heavies to wreck the oil target at the top of the list once and for all. Fie had begun a direct assault on Ploesti’s refineries with attacks on 18 and 31 May, with almost 500 bombers participating in the latter raid. The last week of June he ordered three more strikes, and then five more in July. The July raids cost Fifteenth Air Force nearly 100 bombers—by the end of the month it had lost 30 percent of its bomber strength. Spaatz, though, could count on a steady stream of aircraft and crews to replace the losses, and waged an attrition campaign against Ploesti similar to his Big Week battles against the aircraft industry. Four more attacks followed in August, with the raf joining in the assault with night raids. The Luftwaffe did not oppose the final mission against the refineries on 19 July; intelligence officers estimated that Ploesti’s oil production was now a mere 10 percent of its peak output. The Soviet army overran the smoldering complex at the end of the month. Fifteenth Air Force dropped almost fourteen thousand tons of bombs in the five – month campaign that eliminated nearly half of Germany’s ability to refine oil. In the process it lost 3 50 bombers, 200 fighters, and more than one thousand men.66
Spaatz wanted to continue hammering oil installations, but other requirements diverted him from that effort. Soon after D – Day, the Germans began launching v-i “buzz” bombs against England from northern France and Belgium. While the attacks caused little damage compared to the Luftwaffe’s blitz in the Battle of Britain, they killed almost six thousand civilians in two and a half months and produced widespread anxiety.67 Churchill persuaded Eisenhower to make the launch sites the top target for usstaf and raf Bomber Command. Spaatz began attacking them in mid – June, though he thought the effort yielded minimal results against well-camouflaged targets that had a minimal impact on the war. At the end of the month he met with Eisenhower and persuaded the Supreme Allied Commander to allow attacks against targets in Germany when the weather cooperated, the ground forces did not face an emergency, and the V-weapons did not demand the complete attention of the strategic air forces.68
Nonetheless, the demand for air support from Allied armies continued. Fifteenth Air Force heavies devoted substantial assistance to the “Anvil” landings in southern France in August. Operation “Market Garden,” the airborne assault in Holland, consumed much of Eighth Air Force’s heavy bomber fleet in September. Spaatz reported to Arnold that using heavy bombers to resupply ground and airborne troops for ten days in Market Garden cost Eighth Air Force the equivalent of а в-24 wing for six weeks. During the ten-day span, Spaatz bemoaned, his bombers lost the chance to conduct precision raids against German targets on two days, and radar attacks on another six.69 Spaatz’s deputy commander, Fred Anderson, also voiced his displeasure over the need to provide air support to ground forces. “The Armies cannot move forward without help from the Air,” Anderson confided to Major General Curtis LeMay in early October. “They stay until we blast the way, and once the way is blasted they move the extent that their supplies allow; then they stop. And when they stop the German digs in, and the way must be blasted again before they move.”’0