ISBN 0-7006-1136-3
394 pages

Abbreviations; Acknowledgments; Introduction; photos; tables; Conclusion; Notes; Bibliography; Index

   Other books devoted to flak have been published over the years, but none quite like this one. Ack-Ack, General Sir Frederick Pile's memoir, covers his years as commander of flak defenses in the UK. Brigadier N.W. Routledge wrote an excellent operational/tactical account in his volume of the history of the Royal Regiment of Artillery, Anti-Aircraft Artillery, 1914-1955, with by far the bulk of the book covering World War II. Werner Muller's German Flak in World War II provides a photographic survey, and there are also studies of German flak guns, flak trains, and flak towers. Yet, Edward Westermann's new book stands out as the first comprehensive, integrated account in English of the strategic, industrial, technical, doctrinal, and operational aspects of the entire German ground-based air defense system in the Second World War, with an emphasis on how flak was employed against the Allied strategic bombing campaign.
   Given the massive number of works about the strategic bombing offensive but the much smaller number of books about German flak defenses, it's understandable that some misconceptions have arisen about the role and effectiveness of the German anti-aircraft system. Without wasting time or words, Westermann goes straight to the heart of these misconceptions in Flak, using the first pages of his Introduction to refute three myths about German AA defenses in World War II:

• German AA achieved only limited success against Allied bombers
• German AA cost too much "in terms of both fiscal and personnel outlays" in relationship to results
• Resources devoted to German AA could have been better used building other weapons, especially fighters

   Westermann attends to these points, and many others, in much more detail throughout his excellent book. To begin with, however, the author devotes his first chapter to investigating the evolution of AA defenses before and during World War I. His description of the earliest German AA is especially interesting.

   The origins of German anti-aircraft efforts reach back to the Franco-Prussian War of 1870-1871. The use by the Communards of hot air balloons to escape from the besieged city of Paris resulted in an urgent request by the German army for an effective weapon with which to engage the French balloons. The Krupp armament works quickly began efforts to produce a 36-mm antiballoon gun (Ballonabrrehrkanone, or BAK) mounted on a mobile cart. However, hitting a balloon and damaging it sufficiently to bring it down proved more difficult than originally envisioned. Of the sixty-six balloons known to have left Paris during the siege, the Germans succeeded in bringing down only one, the Daguerre, on November 12, 1870. In fact, the technological and mechanical problems associated with targeting balloons, airships, or aircraft would remain the primary obstacle to the successful engagement of aerial targets by anti-aircraft guns throughout the next three-quarters of a century. For example, German gunners relied on mobility and dispersion to cover the area around the French capital. Still, by the end of 1870, the German army had only six of these guns to cover the entire perimeter of the city. Even when fire could be brought to bear on a balloon, the 36-mm metal slugs, although capable of puncturing the balloon's skin, often inflicted insufficient damage to bring it down. In any event, the French simply began making flights at night, thus minimizing the threat posed by the guns. The ultimate capitulation of the French in 1871 resulted in a thirty-five-year hiatus in the field of German air defense research and development.

   By the beginning of World War I, the Germans had in place an integrated system of fighter interceptors, motorized flak guns, horse-drawn and fixed flak guns, searchlights, and balloon barriers, along with passive defenses such as blackouts, dummy targets, and bomb shelters for civilians. By the end of the war they deployed almost 3000 AA guns and 700 searchlights, all manned by nearly 60,000 men. German flak accounted for 19 percent of Allied aircraft destroyed in combat in the Great War. At war's end, the ground-based air defense system responsible for this success was dismantled under restrictions imposed by the Versailles treaty.
   These restrictions limited guns and forces, but did not limit study, experimentation, debate, and planning. Westermann traces theory and practice in the inter-war years, especially including the clash between proponents of flak and those of interceptors. By 1933, when the Nazi government began expansion of the armed forces, plans were already in place for AA units, and the existing nucleus of "driving sections" (a euphemism hiding the true purpose of mobile flak units) suddenly became the most effective ground-based air defense units among the major powers. In 1935 German AA units were incorporated into Hermann Goering's Luftwaffe. Thanks in part to Goering's clout, this was soon followed by an increase in the number of flak units as well as improved equipment.

   A closer examination of the flak battalions at this time shows not only an increase in numbers but also an improvement in equipment. For example, a heavy flak battalion included 3 batteries of four 88-mm guns and two 20-mm guns each, 1 battery of six 37-mm guns, 1 battery of nine 150-cm searchlights and six sound detectors, and 1 replacement battery. In other words, a heavy flak regiment had twenty-four 88-mm guns, twelve 37-mm guns, twelve 20-mm guns, eighteen 150-cm searchlights, twelve sound detectors, and 2 replacement batteries. In contrast, a regular Flak regiment substituted one heavy flak battalion for a light flak battalion, including 3 batteries of twelve 20-mm guns, a battery of twelve 60-cm searchlights, and a replacement battery, for a total strength of twelve 88-mm guns, six 37-mm guns, eighteen 20-mm guns, nine 150-cm searchlights and twelve 60-cm searchlights, six sound detectors, and 2 replacement batteries. The "new" flak battalions clearly possessed an improved capability and vastly increased firepower in comparison to their predecessors, the "driving sections" of 1933.

   Similar expansion and technological improvements continued throughout the 1930s. During the Spanish Civil War, the Luftwaffe also benefitted from practical operational experience. The Condor Legion included eight AA batteries (one of which was used for training Spanish forces) and on the battlefields of Spain the Luftwaffe learned lessons about how effective AA guns could be in ground combat.
   When WWII began, Germany fielded the "most modern air defense network in the world" and "the best civil defense system." Luftwaffe AA assets were assigned to Army units during the Polish campaign where they engaged enemy aviation and also supported ground combat. Despite successes in the field, it was recommended that attached AA assets should be strengthened, assigned to support forces at lower echelons, and utilized closer to the front. During the Polish campaign and the ensuing Phoney War, German AA made itself felt against early RAF attempts at daylight bombing, even if these actions did not always translate directly into aircraft downed by flak.

   In retrospect, these engagements offered two clear lessons concerning air defenses. First, the effectiveness of flak at low and medium altitudes made bombing attacks from these heights prohibitive during daylight. Second, any standard for judging the effectiveness of flak forces needed to extend beyond the number of aircraft brought down to include the second-order effects produced by the flak forces. By damaging bombers or loosening the bomber formation, the flak was creating opportunities for the fighters to bring their attacks to bear. Throughout the war, many within the Luftwaffe leadership, like Field Marshal Erhard Milch, ignored the importance of these second-order effects in their evaluation of the contributions of ground-based air defenses by focusing on the numbers of aircraft destroyed alone.

   The campaign in the West in 1940 demonstrated the utility of AA guns against tanks, concrete bunkers (including parts of the Maginot Line) and even ships in port as well as aircraft. Indeed, since massive Allied air raids against German cities and industries never materialized, support of ground forces rather than homeland defense became temporarily the major chore for German flak. Nevertheless, the Luftwaffe continued to take very seriously the need for defending against attacks by Bomber Command. With the RAF rapidly discovering that, at least in daylight, it was not true that the bomber would always get through, and the subsequent switch to night bombing, the German flak arm devoted much effort to solving the problems of defending against air attacks with flak at night. Westermann rounds out his description of flak in the 1939-1940 period by—as he does throughout his book—dividing his chapter into a variety of headings: "Problems with Night Fighting," "Radar and Air Defense," "Expanding the Flak Arm and Economic Costs," "Decoys and Deception in Air Defense," "Barring the Sky with Balloons," and "Firing Blind." For all these topics, the author integrates technological details, tactical doctrine, organizational inefficiencies and inter-departmental conflicts, and production statistics. Likewise, as he does throughout the book, Westermann carefully considers responses to measures and counter-measures as the Luftwaffe and the Allied bombers adjust to each other's tactics. In particular, Germany constantly sought to add new flak defenses.

   Hitler's personal involvement proved successful in raising the monthly production of 88-mm guns from 48 per month in the fourth quarter of 1939 to 108 per month by the third quarter of 1940. In contrast, the monthly consumption of 88-mm guns due to excessive wear or destruction averaged a mere 10 guns throughout 1940. However, the production of 88-mm ammunition would not exceed 1 million rounds until the middle of 1941. In any event, the overall strength of the flak forces had risen substantially in the first ten months of the war. By June 1, 1940, the flak arm had 3,095 heavy guns (88-mm and 105-mm), compared with 2,628 in September 1939. In the same period, the number of light flak guns (20-mm and 37-mm) increased from 6,700 to 9,817, while the number of searchlights (60-cm and 150-cm) grew from 3,000 to 4,035. In addition, the flak arm operated over 2,000 sound detectors and 502 fire directors. By the summer of 1940, the Luftwaffe had raised the total of heavy flak guns by 15 percent, light flak guns by 32 percent, and searchlights by 25 percent. In addition, ammunition reserves stood at 5.9 million 88-mm rounds, 5.4 million 37-mm rounds, and 78.2 million 20-mm rounds. By August, the continued expansion of the flak arm required the services of 528,000 men to operate the broad range of ground-based air defense weapons and equipment.

   Westermann opens his chapter on developments in 1941 with the push for radar-directed fire control to replace the more common sound detectors. However, the continued deployment of radar-directed systems was fraught with technical and training problems. Meanwhile, production of 88mm AA ammunition had been reduced after the fall of France and the improvement in flak accuracy associated with radar meant that fewer shells would be expended thanks to the reduced need for "barrier" fire. Nevertheless, production quotas were raised from the post-France level of one hundred thousand shells per month to two million rounds per month. Due to various bottlenecks, production actually peaked at 1.44 million rounds per month at the end of 1943.

   The difficulties associated with the production of munitions provide some insight into the complexity and scale of effort needed to create and maintain the air defense units. There were, however, other obstacles and problems associated with the increased consumption of munitions. The high expenditure of ammunition resulted in the need to replace the barrels of the flak guns at shorter intervals, a problem exacerbated by the fact that flak gun barrels wore out more quickly than regular artillery barrels because of the flak projectiles' higher exit velocity. Throughout 1941, the Wehrmacht lost an average of forty-one 88-mm guns per month due to excessive wear or destruction in combat, a rate four times greater than in 1940. The problems associated with the shortages of replacement barrels and 88-mm ammunition even led to an order in February to fire only on aircraft that "are considered to be attackers." Additionally, the order directed that aircraft flying in the vicinity of flak sites were to be engaged only if "favorable firing situations" existed. The order limiting engagement of the enemy was rescinded two weeks later with the directive that "the enemy is always to be engaged, irregardless of when and where he is met."

   Combat on the ground in Russia and Africa in 1941 proved again and again that the Luftwaffe's precious AA guns were invaluable against enemy tanks, often performing the decisive role in tactical engagements. From this point the Luftwaffe had to fend off increasing demands from the Army for more and more flak weapons. In April Hitler ruled against creation of an Army flak arm, but demands remained insatiable.
   Westermann also continues his emphasis on the importance of Germany's decoy installations, quoting figures showing surprisingly large percentages of RAF bombs falling on dummy targets. The Luftwaffe did not rely on decoys alone. A new version of the 88mm gun was ordered in 1941, emerging as "pound-for-pound the most capable flak gun of the war." Extra guns were also added to flak batteries during the year. All in all, German defenses proved strong enough to decisively defeat a major RAF raid against Berlin in November, and the Luftwaffe was at this point clearly winning the strategic air war. The cost? By the end of 1941, this mean "[t]he devotion of over one-third of the Wehrmacht's entire ammunition budget to anti-aircraft munitions...."
   By 1942 the numbers of heavy AA guns, light AA guns, and searchlights had increased substantially for defense of the Reich against Bomber Command. In addition, growing numbers of AA batteries were equipped with gun-laying radar, and the Luftwaffe introduced "Malsi converters" which allowed AA batteries without radar to use radar data from a remote site. Unlike searchlights, radar could find RAF bombers even when hidden by 10/10 cloud. Gun-laying radar also enabled flak to operate accurately in conditions when Luftwaffe interceptors had to remain grounded.
   Despite some claims to the contrary by other historians of the air war, Westermann finds ground-based air defenses to have been nearly as effective as fighter defenses during 1942.

   Finally, the official RAF history recorded the estimated causes of losses in night raids between July and December 1942 as 169 aircraft lost to fighters and 193 aircraft lost to flak, a ratio of 1.14 to 1 in favor of the flak. Furthermore, in the same period the estimated number of aircraft damaged "beyond repair" by fighters was 11 versus 23 for flak, while aircraft damaged but repairable numbered 142 for fighters and 918 for flak. These figures clearly refute the exaggerated claims attributed to night fighter success and demonstrate how the achievements of Germany's flak defenses have been underestimated in many postwar histories of the air war.

   In February 1942 "Bomber" Harris replaced Richard Peirse as Commander-in-Chief of the RAF's Bomber Command. Under his stern guidance, the night bombers began intensifying their attacks and making massed raids over important targets. In May 1942 Harris launched the first thousand-bomber raid.
   Given such intensification of the Allied bombing campaign, the Luftwaffe had to scramble to respond effectively. Dummy/decoy sites were increased and smoke generators used to conceal targets. And as always, the number of AA guns increased.

   Despite the manifold increase in the size of the Luftwaffe's ground-based defense forces, neither the German economy nor its manpower base could support the necessary expansion to protect every important target within Germany and the occupied territories. One response was an attempt to rely on mobility to move flak forces more quickly to threatened areas. For example, the Luftwaffe high command ordered the construction of more heavy and light railroad flak battalions capable of being moved quickly throughout the Reich. The railroad batteries became the flak elite, receiving the most modern equipment and the best-trained personnel. By the end of 1942, there were fifty batteries of railroad flak. Another initiative focused on accelerating the ongoing expansion of the number of weapons in each of the heavy gun batteries from four to six barrels to increase the firepower of the individual batteries.
   Increasing the number of guns per battery certainly offered one means of raising the volume of firepower per battery. In fact, the concept eventually led to the creation in the spring of 1942 of "superbatteries" (Grossbatterien) that linked three batteries of four guns each to one centrally located fire director. The problems in transmitting firing data to twelve different guns at three separate sites proved "acute." However, with the introduction of the improved Wurzburg gun-laying radar, the Luftwaffe largely had mastered this problem by the middle of 1942. In the superbatteries, the three flak gun batteries formed an equilateral triangle, with a gun-laying radar and three fire directors located in the center of the triangle. The radar fed the firing information to one of the directors, which then electrically transmitted these values to each of the batteries; the remaining two fire directors were kept in reserve in case of the failure of the primary device.
   The superbatteries offered three primary advantages for the air defense crews. First, the ability to increase the concentration of directed fire resulted in a greater probability of shooting down an engaged aircraft. Second, the consolidation of three batteries with one centrally controlled fire direction center allowed the flak units to reduce the overall number of administrative and support personnel. Finally, the superbattery also reduced the number of technical support personnel needed. However, the advantages of the superbatteries had to be weighed against several disadvantages. First, they were more vulnerable to attack and disruption due to the centralization of the fire direction function and the thousands of yards of cable and wiring needed to provide the gun batteries with firing solutions. Second, they required a great deal of space. Third, the complexity of controlling twelve guns did not allow for the coordination with fighter aircraft in the flak engagement zone. Admittedly, with single batteries this coordination proved difficult, but with three batteries it was essentially impossible. Finally, the superbatteries required extremely well trained personnel to be effective.

   The Luftwaffe also stepped up production of the 88mm/Model 1941 guns and the enormous 128mm guns, including the double-barreled version. Goering ordered large numbers of batteries built into fixed positions, thus saving in associated production overhead for transport and personnel in comparison to mobile batteries. "In the end, economic considerations outweighed tactical concerns as the Luftwaffe increasingly chose to build fixed anti-aircraft sites in place of mobile guns, a decision that would have important consequences as the fronts in the east and the west began to collapse in late 1944."
   Similarly, manpower considerations dictated that the Luftwaffe in 1942 began to rely on a variety of new sources for flak personnel. These included Home Guard AA units made up of factory workers and local residents, Alarmflakbatterien units comprising local desk-bound Wehrmacht personnel, the Blitzmaedel ("lightning girls") who soon handled most communications duties, and even POWs enticed by the prospect of better conditions.
   Westermann devotes considerable attention to two intriguing projects supported by the Luftwaffe's Inspector of Flak, von Axthelm, in 1942: anti-aircraft rockets and super-heavy 200mm and 250mm flak guns. Along with other proposals, the "Flak Development Program of 1942" offered both realistic and fanciful goals for defeating the increasingly destructive bomber attacks. The author demonstrates considerable expertise as he analyzes the program, its technological underpinnings, and what it meant to the war effort as a whole, as well as the ins and outs of the important Luftwaffe conference on 1 September 1942 regarding ground-based defenses.
   Although many did not yet realize it, all of the Luftwaffe's planning and preparations in 1942 for new and better AA defenses would soon become critically important. Not only was Bomber Command increasing the weight of its attacks, but the US 8th Air Force, although it did not make itself strongly felt during 1942, had joined the battle.

   At the end of the year, Goring praised flak as the "backbone" of the air defense system on all fronts. Clearly, ground-based air defenses remained a key element in the Luftwaffe's air defense system. The total number of confirmed aircraft shootdowns for all theaters since the start of the war stood at 8,707. Additionally, flak crews serving in the east and in North Africa achieved excellent results in combat against Soviet and British tank forces. For example, one flak division on the Eastern Front alone received credit for the destruction of 300 aircraft and 260 tanks between April 10 and November 3, 1942. Likewise, Luftwaffe decoy and deception efforts continued to enjoy on occasion a high degree of success against RAF night bombing attacks. In addition, the number of flak guns and the amount of air defense equipment had increased dramatically in the course of the year. The expansion of the flak force proved to be, however, a two-edged sword, for the Luftwaffe had to employ less-qualified men and women in an attempt to keep pace with the growth of the various ground-based air defense sites. Indeed, the rapid expansion of military and civilian flak forces had produced visible cracks in the air defense edifice. From the Luftwaffe's perspective, the mobilization of men and women from the civilian sector resulted in a decrease in the quality and readiness within the air defense arm. Additionally, despite the expansion of the night fighter force, the flak and searchlight batteries clearly remained the primary means for defending the Reich. Up to this point, the air defense system for the most part had worked well. RAF raids against Lubeck and Cologne had temporarily shaken many German civilians and angered Hitler and the rest of the Nazi leadership, but they had failed appreciably to affect morale or lessen support for the regime. However, the critical question facing the Luftwaffe's leaders at the end of 1942 was whether they were adequately prepared for operations in the coming year.

   Following heavy German manpower losses at Stalingrad and in North Africa in early 1943, the Luftwaffe expedited the mobilization of Flakhelfers of "all men between the ages of sixteen and sixty-five and all women between the ages of seventeen and fifty." Overall readiness tended to suffer, however due to reduced training periods and the transfer of equipment and instructional cadres to operational units. While German industry struggled to produce sufficient AA guns, gun-laying radars, searchlights, and related equipment, measures to improve AA efficiency were introduced: expanded use of devices for sharing radar, reorganization of batteries to include increased numbers of guns to cut down on organizational overhead, and further reduction of mobile flak batteries in favor of fixed defenses. For the first time, shortages of AA ammunition began to occur, including lessening availability of training rounds.
   On top of these problems, Westermann also illustrates diversion of AA assets and dispersal of effort by showing how the V-1 program drew heavily from the Luftwaffe's flak arm. This dispersal of effort was also true in continued attempts to develop the "Waterfall" radar-guided AA missile program.
   While the Luftwaffe attempted to counter RAF strategies and develop new technologies, Bomber Command made its own technological leap with the introduction of "Window"—radar-blinding aluminum chaff—during raids over Hamburg in July 1943. The Germans quickly began work on counter-measures, but Westermann deems 1943 the low point for German ground-based air defenses as the Allies began to gain the upper hand in the air war and senior Luftwaffe leaders began to lose faith in the ability of flak to defend the Reich. Fighters, it was concluded by many, could do a better job of staving off the bombers.
   In January 1944, the ebb of flak defenses was illustrated by orders that AA guns must not fire at targets above 16,000 feet in order to allow night fighters to intercept bombers directly over Berlin without being attacked by friendly flak. Nevertheless, production of AA guns, searchlights, and gun-laying radar continued to rise. Of these, development and production of radar sets proved to be a big bottleneck for the flak arm in 1944. Even more so, however, production of AA ammunition could not keep pace with demand.
   As the number of flak batteries continued to grow, so grew the need for personnel. During 1944 alone, the flak arm increased by 250,000 men and women.

   An examination of the composition of the 14th Flak Division in October 1944 provides a clear indication of the diverse nature of German flak personnel by this stage of the war. The division primarily was responsible for the defense of the Leuna synthetic oil refinery and was composed of the following groups:

Regular Luftwaffe personnel	28,000
Labor Service personnel	18,000
Male Luftwaffe auxiliaries	6,000
Female Luftwaffe auxiliaries	3,050
Hungarian and Italian volunteers	900
Soviet POWs	3,600
Others	3,000
Total	62,550

   Westermann goes into considerable detail describing how the ability of American long-range fighters to escort 8th Air Force bombers over Germany jolted the Luftwaffe's air defense equations. Fighters, upon which the Luftwaffe had come to rely more heavily in 1943 for defense of the Reich, were no longer able to attack American bomber formations with relative impunity. Instead, they were forced to deal with escorts which inflicted mounting losses on the Jagdwaffe while protecting the bombers. With interceptors no longer in the ascendancy in daylight, the flak arm again shouldered a more important role. Westermann notes that flak "engagements by visual measures were five times more effective than engagements using radar control." This meant that, with or without Window, the American daylight attacks tended to suffer more heavily from flak than the British nighttime raids.
   The Luftwaffe responded to the altered equation by continuing to increase the number of flak guns, expanding the size of individual batteries, introducing improved gun-laying radar, using grooved, high-splinter AA rounds, and developing better anti-jamming gear. All the advances meant more AA fire and more accurate AA fire. Westermann also continues to emphasize German use of dummy targets, radar-reflecting decoys, camouflage, dummy AA batteries, and smoke screens to deceive and confuse the bombers. In particular, the author discusses at length smoke generators and the eventual shortage of smoke-generating chemicals.
   At the time when the flak arm found itself returning to its original role as the primary defense against bombing of the homeland, developments at the front altered the air defense algorithm even further. With the Allied landings in Normandy in June 1944, the need to strengthen the AA defense of the Reich suddenly conflicted with the need to divert flak weapons to the new ground front. When the invasion came, the Luftwaffe transferred almost 200 batteries to France. "This transfer set an ominous precedent, as the withdrawal of flak forces from the Reich's defenses to the front lines became a common practice during the last ten months of the war, causing an eventual hemorrhage within the home front's ground-based air defenses. At the front, the AA units were far more likely to be used against ground targets than enemy aircraft."
   In Germany, remaining AA was increasingly deployed (even transferred from Berlin) to defend synthetic oil plants. While defenses of these installations were beefed up substantially, the Luftwaffe's earlier decision to build fixed rather than mobile flak guns meant rapid transfer of batteries was difficult or impossible, and this also affected the transfer of guns to the fighting fronts as well as their withdrawal.
   For lack of oil and trained pilots, mounting numbers of German aircraft sat idle while fleets of bombers roared over Germany. In mid-August, Hitler raged against the Jagdwaffe, insisted all fighter production must be halted, and ordered a vast increase in flak defenses. Despite the unreality of Hitler's demands, the AA batteries continued to assume the burden of defense against air attack on the Reich during daylight. The Luftwaffe's night fighters were in better shape and continued to offer stiff resistance to Bomber Command. By the end of 1944, however, even the night fighters were nearly impotent against the bomber streams. By the last months of the war, as at the beginning, flak made up the main defense against bombers.

   By the autumn of 1944, the ground-based air defense force numbered 1,110,900 persons, with 448,700, or 40 percent, coming from outside the Luftwaffe. The non-Luftwaffe personnel included 220,000 Home Guard, Labor Service, and male high school auxiliaries; 128,000 female auxiliaries; and 98,000 foreign volunteers and prisoners of war. The fact that 40 percent of the Luftwaffe's flak arm consisted of auxiliaries indicates the extent of the personnel crisis facing the German armed forces by the last year of the war. In August 1940, the Luftwaffe's flak arm had included 791 heavy flak gun batteries, 686 light flak gun batteries, and 221 searchlight batteries operated by a total of 528,000 regular and reserve Luftwaffe personnel. Four years later, the size of the flak arm had increased to 2,655 heavy flak gun batteries, 1,612 light flak gun batteries, and 470 searchlight batteries. Despite the fact that the total number of batteries had almost tripled, the number of service personnel had grown by only 134,000, while civilians, high school students, foreign nationals, and prisoners of war increasingly provided the basis for the Luftwaffe's battle against Allied bombers. In fact, flak units stationed within the Reich consisted of only 10 percent fully qualified regular military personnel by the latter stages of the war.

   Production of AA guns also continued to rise (as did the numbers of guns which wore out and required replacement), but production of AA ammunition fell farther behind consumption. As enemy forces closed in, more and more flak batteries were shifted to the ground campaign. "In sum, the Luftwaffe transferred a total of 555 heavy and 175 medium/light flak batteries to the fighting fronts during the last eight months of the war. The mass transfer of flak batteries to the combat fronts in the closing stages of the war effectively stripped entire areas within Germany of their air defenses, opening these areas to unimpeded aerial attacks."
   With battery after battery transferred to the front, with ammunition shortages, personnel shortages, transport shortages, and the overwhelming night and day strength of Allied bombing attacks, the flak arm could not win the air campaign alone and it began to break down, along with the remainder of the Wehrmacht, in the final months of the war. In the end, nothing could prevent the bombers from getting through.
   Westermann concludes his book with sixteen pages of detailed analysis of Germany's flak defenses during the war. In particular he returns to the three myths listed in his Introduction and relentlessly wields quantifiable evidence to demolish the widely held views that flak achieved only limited success, that flak cost too much, and that resources devoted to flak could have been better used elsewhere.
   Flak is absolutely one of the very best WWII-related books of the year, and it fills a large void in the literature of the air war over Germany with a comprehensive account of all aspects of the Luftwaffe's ground-based air defense system—including dummy targets, dummy batteries, radar-reflecting decoys, smoke generators, sound detectors, searchlights, gun-laying radar, and barrage balloons—rather than just anti-aircraft guns. Westermann covers strategic planning, operational deployment, technology, resources, and production, competing personalities and doctrines, personnel shortages, the shifting relationship between fighter defenses and ground-based defenses, and much more. Likewise, he simultaneously watches the big picture while keeping an eye on such mundane details as the implications of increased use of rock salt as filler in AA shells due to decreased production of explosives. In sum, Westermann proves incontrovertibly that anyone studying the strategic bombing campaign strictly from the perspective of airpower has missed an important element of the equation. Flak should be required reading for students of the strategic bombing campaign. At a bare minimum, anyone interested in the air war should be required to read his concluding chapter. And no one should miss his final words.

   Prior to World War II, Luftwaffe doctrine recognized that both flak and fighters were integral elements in a coordinated air defense network. Despite this doctrinal prescription, the flak arm clearly entered the war as the primary instrument (Haupttrager) of the Luftwaffe's homeland air defenses. With good reason, numerous participants in the air war, as well as postwar historians, have identified the failure of the Luftwaffe to increase the size of its fighter force in 1941 as the turning point in the battle for air superiority over Germany. In retrospect, it is apparent that, ceteris paribus, a decision to pursue increased fighter and pilot production in 1941 would have improved the position of the Luftwaffe in later years. However, the Luftwaffe chose instead to rely on its ground-based air defenses. As the Allied air offensive intensified in the final two years of the war, the flak arm clearly failed to meet the high expectations placed on it by the Luftwaffe leadership. In the historical record, the flak arm has paid for its failure to meet these expectations far more severely than it deserved. The myopic focus on the benefits of a fighter force has produced a literature that often fails to consider the many hidden, and admittedly often nonquantifiable, effects of the flak arm. Furthermore, a tendency to focus solely on the flak batteries has obscured the varied and important contributions of other elements within the Luftwaffe's ground-based air defenses. In the end, Hitler's vision of a flak battery protecting every German town and village proved as illusory as his quest for a millenarian empire. The Luftwaffe's ground-based air defenses, by themselves, could not prevent the devastation of Germany from the air; however, this failure should not obscure the significant contributions made by these defenses between 1939 and 1945. The events of 1939-1945 clearly demonstrated that the air war could not be won with ground-based defenses alone, but these events make it equally apparent that without these defenses, German cities and factories quickly would have been bombed into ruins. After the war, the commanding general of the USAAF, General Henry "Hap" Arnold, observed, "We never conquered the German flak artillery." In the end, it did not matter because the flak arm could not change the fate of the Reich nor save German cities and industry from destruction. Nevertheless, the efforts and performance of these defenses clearly deserve more credit than they have received.