The Bombing War: Europe 1939–1945

by Richard Overy

  Though the defensive threat was less, the question of what to bomb was not easily answered, partly because detailed intelligence on Italian industry and communications after the German occupation in September 1943 was difficult to acquire and partly because of the persistent uncertainty surrounding the fate of Italy’s historic heritage. There were disagreements not only over what to bomb, but what not to bomb. Unlike the British attitude, Washington recognized that it was politically expedient to preserve Italian culture from unnecessary damage in order to limit accusations of Allied barbarism. Therefore, on 20 August 1943 Roosevelt gave his approval for the establishment of the American Commission for the Protection and Salvage of Artistic and Historic Monuments in Europe. The Commission was advised by an academic working group set up by the American Council of Learned Societies, which produced 160 detailed maps of Italian cities using the Italian Baedeker guide, with most cultural monuments clearly marked. These were sent to MAAF and added to the dossiers for briefing officers when organizing an operation.210 In April 1944 a list was distributed to all Allied air forces in Italy, listing cities in three categories for bombing purposes. The first category comprised Rome, Florence, Venice and Torcello, which could only be bombed with specific instructions from the High Command; the second category of 19 historic cities, including Ravenna, Assisi, Pavia, Parma and Montepulciano, were not regarded prima facie as militarily important, but could be bombed under circumstances of military necessity; the third category was made up of 24 cities, most with architecturally outstanding city centres, such as Brescia, Siena, Pisa, Bologna and Viterbo, which were deemed to contain or be near military objectives. These could be bombed freely ‘and any consequential damage accepted’.211 If any city in categories two and three was occupied by the enemy in a zone of operations, no restrictions were to be observed. Otherwise crews were instructed only to bomb objectives by day if not obscured by cloud, and by night if illumination made the precise military objective sufficiently clear. The rules gave a great deal of discretion to the individual pilot, and in practice, given the wide inaccuracy of high-level bombing, in Italy as elsewhere, protection for cultural monuments was observed only within wide operational limits.

  Even the cities in category one came to be bombed when military circumstances dictated. ‘Nothing,’ wrote Eisenhower for the Allied forces in Italy, ‘can stand against the argument of military necessity.’212 In February 1944 MAAF headquarters decided that the rail centre at Florence would have to be bombed as part of the effort to cut German communications. British Air Marshal John Slessor told the Air Ministry that only the most experienced crews would be used. He pointed out that the famous Duomo was at least a mile distant from the target: ‘it would be very bad luck if any of the really famous buildings were hit’. On 1 March Churchill was asked for his view; he scribbled on the letter ‘certainly bomb’, and the following day the chiefs of staff approved the raid.213 Luck stayed with the bomber crews this time and the Duomo remained intact. They were told that some damage to the city was inevitable, but should not be construed as ‘limiting your operations’, which explains the damage to two hospitals and the death of 215 Florentines.214 On 20 April 1944, bombs fell on Venice for the first time, contrary to instructions. An investigation showed that 54 American bombers, finding their targets in Trieste covered by cloud, defied orders and bombed the port of Venice as a target of opportunity from 24,000 feet. Once again, luck was in their favour; the historic heart of Venice suffered no damage.215

  This was not the case with the efforts to avoid bombing Vatican City. The bombing of Rome was continued despite the persistent efforts by the Papacy, the Badoglio government (now based in southern Italy in the Allied zone) and even Mussolini’s new Salò regime to get the Allies to accept the status of open city for the capital. Roosevelt, with a large Catholic minority in the United States, was more inclined to discuss the possibility, but Churchill worried that if Rome were made an open city, it would hamper Allied military efforts to pursue the Germans up the western side of the peninsula. The Combined Chiefs discussed the issue in late September but it remained deadlocked.216 Then on 5 November four bombs were dropped on the Vatican, causing serious damage to the Governatorato Palace, the seat of Vatican government. The first reaction from the British ambassador to the Vatican, Sir Francis D’Arcy Osborne, was to blame the Germans for the raid as a propaganda stunt, but a few days later investigations showed that one American aircraft, bombing at night, had lost contact with the rest of the force and dropped bombs in error.217 Roosevelt once again tried to revive British interest in the demilitarization of Rome, but the British remained adamant that it would place too many restrictions on the Allied ground campaign, and on 7 December Roosevelt finally conceded that it was ‘inadvisable’ to pursue the matter any further.218 Rome continued to be bombed and over 7,000 Romans died in the course of the year from the first bombing in July 1943 to the Allied capture of the city in June 1944. The accidental raid on the Vatican showed how difficult it was under conditions of night, poor weather, or human error to avoid widespread damage to Italy’s cultural heritage even with the best of intentions.

  There was nevertheless nothing accidental about the most controversial raid of all, against the fourteenth-century Benedictine abbey on the mountain top overlooking the small town of Cassino on 15 February 1944. The building dominated the Liri Valley position where the Allied armies were attempting to unhinge the German defences along the so-called Gustav Line, which stretched from the coast north of Naples to Ortona on the Italian Adriatic coast. On 4 November 1943 Eisenhower wrote to the Allied Fifteenth Army Group that the Monte Cassino abbey was a protected building; the Pope asked both the Germans and the Allies to respect its sacred status. When Eisenhower was replaced by Wilson as Supreme Commander in January 1944, the principle that historic buildings would only be hit under conditions of ‘absolute necessity’ still prevailed, though it did not prevent the bombing of the Papal estate at Castel Gandolfo on 11 February, which destroyed the convent and killed 27 nuns.219 At Cassino all attempts to dislodge the German forces from the small town or the hilltop had failed and it is not difficult to understand why frustration with the slow progress of the campaign and the likelihood of high casualties encouraged the local army units to ask for air assistance. There were strong rumours (but no hard evidence) that the abbey was already occupied by German forces. On 11 February the 4th Indian Division, planning its assault, made a request for ‘intense bombing’ of the hilltop and its surroundings, including the monastery; on 12 February the commander of the Indian Division, Maj. General Francis Tuker, insisted that the monastery should be destroyed whether it was occupied by the Germans or not, since it would easily become a strongpoint if the Germans chose to use it.220 The decision should have been made at the highest level by the Combined Chiefs of Staff and agreed by Spaatz, but in the end it was made by General Harold Alexander, overall army commander, and endorsed by Wilson. Eaker was instructed to launch an attack on 15 February using both strategic and tactical forces. He flew in a light plane over the abbey the day before and later wrote, to justify the attack, that he could see it was full of soldiers, radio masts and machine-gun nests, though his initial judgement was quite different.221 The following day wave after wave of heavy and medium bombers pounded the monastery with 351 tons of bombs, killing 230 of the Italian civilians who had taken refuge in the abbey precincts.

  The destruction was welcomed by the troops on the ground, who were seen to cheer as the bombers flew in, but the results of these raids (and attacks by Kittyhawk and Mustang fighter-bombers during the two days that followed) were mixed. The vast abbey walls remained intact, in places to a height of 30 feet, making the gutted building ideal for the German forces who now obligingly occupied it as a hilltop fortress from where they repelled the Indian and New Zealand efforts to dislodge them. The operation suffered from the usual bomb pattern, some bombs destroying the headquarters of the local Eighth Army Commander, General Oliver Leese, three
miles from the abbey, and the French Corps headquarters 12 miles away.222 The publicity surrounding the destruction, much of it hostile, forced the chiefs of staff to investigate who had ordered the bombing and why. On 9 March Wilson replied that the abbey building was undoubtedly ‘part of the German main defensive position’ and had to be eliminated to ensure success.223 Slessor, Eaker’s deputy, recalled in his memoirs that no one among the troops would have believed for a moment that the Germans were not using the building as a fortress, ‘so the Abbey had to go’, but he was critical of what the bombing actually achieved given that it took three more months to capture the hilltop, now fully occupied by the enemy.224 A War Office investigation in 1949 into the circumstances of the bombing finally confirmed that there had been no evidence of German occupation to justify the raids, except for an unsubstantiated claim that a telescope had been glimpsed from a window. Eyewitness accounts were collected from Italian women who had sheltered in the abbey during the bombing. ‘Even allowing for the excitable tendencies of women of Latin race,’ ran the report, their testimony gave a credible if ‘prosaic’ account of what happened. Some 2,000 from the population of Cassino had sought shelter on German advice in the church of San Giuseppe behind the abbey; on 3 February, after angry protests from the crowd of evacuees, some of whom had been wounded by shellfire, the monks let them into the abbey. There were no German soldiers or equipment to be seen, except for two German medical officers tending to the wounded Italians. After the bombing, the civilians made their way where they could. The four women who gave accounts of the abbey reached Allied lines and were interviewed less than two weeks after the raid had taken place.225

  The Monte Cassino raid was one of the few times that the strategic bombers were asked to support a ground operation directly. A few days later they also obliterated what was left of the town of Cassino itself. In both cases the result was to hamper army efforts to profit from the bombing. On 16 April 1944 Slessor wrote to Portal to complain about how counterproductive heavy bombing was on the battlefield itself: ‘we hamper our own movement by throwing the debris of houses across roads and making craters that become tank obstacles … we are inevitably bound – as we did at Cassino – to cause casualties to our own people …’.226 Most of the bombing that took place in 1944 and 1945 was directed further away from the battlefront, designed to hamper German communications throughout Italy and to destroy Italian industries working directly to German orders. The communications campaign was the more important. Italian geography worked both for and against the Allies. The narrow peninsula with its mountainous spine meant that communication by road and rail was mainly confined to narrow channels running down the eastern and western coasts of Italy. These channels represented tempting targets for interruption. On the other hand, the Allied armies were also confined to the hilly coastal zones where there were innumerable natural barriers to favour a defending army. In the winter, mud, heavy rain and snow slowed up any ground advance, while poor weather restricted air attacks on transport and allowed the enemy time to restock and reinforce.

  The origins of the planning for a systematic campaign against communications lay in the hurried survey of the bombing of Sicily carried out by Solly Zuckerman, who among his many duties had been allocated in 1942 to the British Combined Operations headquarters as a scientific adviser. In January 1943 he was sent out to the Mediterranean theatre to investigate how Rommel had managed to escape across Libya despite massive Allied superiority on the ground and in the air. Zuckerman stayed on in an advisory role and was asked to supply evaluations for the invasion of Sicily in July 1943, for which he recommended attacking the ‘nodal points’ of the Sicilian and south Italian railway network, and particularly railway repair shops, depots and shunting yards. His advice was followed and his eventual report, based on a survey of the results in Sicily and southern Italy, suggested the campaign had been ‘an outstanding success’.227 Early in 1944 MAAF discussed the possibility of applying the Zuckerman model to the railway system in central and northern Italy to cut Kesselring’s forces off from the supply chain. The preference was for attacks on rail centres rather than bridges and viaducts, which Zuckerman thought were too difficult to destroy, but there was considerable support among American planners for bridge-bombing using fighter-bombers and medium bombers for a task which called for effective precision. In the end, the communications campaign targeted both.

  On 18 February Eaker issued a directive for the communications campaign, detailing the northern marshalling yards for the strategic air forces and the rail links further south for the tactical forces.228 The Fifteenth Air Force targets were the main railway yards at Padua, Verona, Bolzano, Turin, Genoa and Milan, with secondary targets at Treviso, Venice Mestre, Vicenza and Alessandria. The tactical air forces were detailed to attack rail facilities in central Italy, at least 100 miles from the German front line to maximize the strain on enemy road traffic.229 The campaign was given the codename Operation ‘Strangle’, to indicate its purpose, and lasted from 15 March until 11 May using every kind of aircraft available. The heavy bombers dropped 10,649 tons, the tactical air forces a total of 22,454, for a total loss of 365 aircraft, chiefly fighter-bombers and mainly to anti-aircraft fire.230 Of this total, two-thirds were dropped on communication lines. In April a second campaign was ordered to coincide with an Allied ground assault designed to push the German army back past Rome. This operation was codenamed ‘Diadem’ and lasted to 22 June, by which time Rome was in Allied hands and German forces were retreating rapidly towards a new defensive ‘Gothic Line’ north of Florence. This time 51,500 tons of bombs were dropped, 19,000 by the Fifteenth Air Force, for the loss of only 108 bombers, a rate of only 0.4 per cent of all sorties. Of this total tonnage, three-quarters fell on transport targets.231 The outcome was again mixed. The destruction of bridges and viaducts proved more effective than the assault on marshalling yards, which could be used for through traffic even when there was extensive damage. A disappointed evaluation by the MAAF Analysis Section showed that repairs were quickly carried out on rail centres in northern Italy and through tracks reopened. ‘Military traffic was not hindered to a significant degree by these attacks,’ the report concluded. Nor did they cause ‘complete internal economic collapse’.232 Kesselring, when interviewed in August 1945 after the end of the war, confirmed that the transport plan had not been a great success. Bridges were quickly replaced by pontoon bridges, camouflaged in some way; urgent countermeasures had been taken to restore road and rail links. An air strategy exclusively centred on cutting off supplies, Kesselring concluded, was not likely to be effective.233

  The second set of targets for strategic attack lay in the surviving industry of the area occupied by German forces in northern and central Italy. As soon as the Italian surrender was certain, Albert Speer, the German Minister for Armaments and War Production, was appointed on 13 September 1943 plenipotentiary for Italian war production; General Hans Leyers acted as his permanent deputy in Italy.234 The decision to exploit Italian production was taken for a number of reasons: first, to be able to supply German forces in the field with finished or repaired weapons; second, to supply Germany with additional equipment, resources and raw materials; and third, to act as a large subcontracting base for components, engines or subassemblies where there was a shortage of capacity in Germany. A number of committees were established to oversee the transition of Italian industry to German orders, but the priority was the exploitation of the Italian aircraft industry. Four companies made parts for Focke-Wulf, Heinkel, Messerschmitt and Junkers, while Alfa Romeo, Fiat and Isotta Fraschini produced the Daimler Benz DB605 and the Junkers Jumo 213 aero-engines. Once it was evident that production could be continued rather than have machines and labour transferred to Germany, Italian producers cooperated with the German occupiers; workers, though in general hostile to both the Germans and the new Mussolini republic, had little choice but to work or face unemployment or deportation.235 In some cases German intervention encouraged indust
rial modernization and increased productivity in an industry that had failed to adapt to the needs of war, but the revival of production faced numerous obstacles in the supply of materials, transport facilities and machinery. Yet once it had begun, the major industrial regions again became targets for the Allied strategic air forces. Heavy raids were made in the spring and summer of 1944, hitting a total of 420 plants, particularly in the armaments, engineering and steel sectors, and Italian oil depots at Trieste, Fiume and Marghera.236 Extensive damage was done to industrial buildings, but a regular toll of Italian civilian lives was exacted with each raid, which included low-level strafing of workers. One of the worst was the raid on Milan on 20 October 1944, which resulted in some of the aircraft dropping their bombs in error on residential districts, killing 614 people, including 184 pupils and 19 teachers at the Francesco Crispi school, more than three times the number killed in all the other 17 raids on the city in the course of the year.237