Strategic bombing is a military strategy used in a total war with the goal of defeating an enemy nation-state by destroying its economic ability to wage war rather than destroying its land or naval forces. It is a systematically organized and executed attack from the air which can utilize strategic bombers, cruise missiles, or nuclear-armed fighter-bomber aircraft to attack targets deemed vital to an enemy's war-making capacity. It differs from terror bombing in that the latter targets the enemy civilian population, either to bend it to the aggressor's will or to punish it for political actions, such as the World War II bombing of Rotterdam to force its surrender, or the 1941 bombing of Belgrade for "treachery".
As strategic bombing aims to undermine an enemy nation-state's ability to wage war, strategic bombers need to be able to reach targets throughout most or all of that nation, and so have tended to be larger, longer-ranged aircraft. Strategic bombers have also been used to support major military ground operations, such as the isolation of Normandy through the bombing of transportation hubs throughout northern France in support of the D-Day invasion, or the carpet bombing of the Axis front lines west of St. Lo in support of Operation Cobra.
An aerial attack strategy of deliberately bombing and/or strafing civilian targets in order to break the morale of an enemy, make its civilian population panic, bend the enemy's political leadership to the attacker's will, or to "punish" an enemy, while strategic in nature, is more correctly termed terror bombing.
Strategic bombing by multiple modern strategic bombers like the B-52 can be likened to an hour during the Somme bottled into a thirty-second time period. However, some believe this delivery method has been rather ineffective in attacking a nation's warmaking capability, due to the imprecise nature of the attack. Others cite the destruction of enemy infrastructure, resources expended on civil defense and physical protection of sites, and the reallocation of military resources away from the battlefield in order to staff response and air and ground antiaircraft assets as proof of its efficacy. In either case, the unintended mass civilian casualties, terror caused, and ethical questions raised draws adverse long-term attention to the morality of strategic bombing.
Carpet bombing, often confused with strategic bombing, is the use of strategic air assets for operational objectives in support of ground forces. Its use during Operation Cobra is the best-known example. Carpet bombing is viewed ambivalently by ground forces, due to the nigh-inevitable friendly casualties caused by bombers dropping their ordnance short of the aiming point, either through error or "bomb creep".
The use of "smart" weapons is preferred by some nations for two reasons. First, it can be less devastating. Due to the greater accuracy (the smaller CEP) of precision guided weapons, there is less risk of civilian casualties. The second reason is the more-focused damage associated with precision weapons. Strategic bombing can destroy an entire block, but miss the vital components of a factory. Precision weapons can attack precise components of designated targets, increasing the likelihood of a successful attack. However, the 'shock' value of precision bombing is less severe than of area bombing. Unless multiple precision weapons are used, an enemy may seek cover or disperse to different parts of the targeted area. Additionally, area bombing can have an initial significant psychological effect, as the bombing of cities early in World War II terrified their citizens.
Strategic bombing was first used in World War I, though it was not understood in its present form. The first strategic bombing mission of the war was likely the dropping of five bombs on the Gare L'Est train station in Paris on August 30 1914. Within a year or so, specialized aircraft and dedicated bomber squadrons were in service on both sides. These were generally used for tactical bombing: the aim was that of directly harming enemy troops, strongpoints, or equipment, usually within a relatively small distance of the front line. Eventually, attention turned to the possibility of causing indirect harm to the enemy by systematically attacking vital rear-area resources.
The first-ever dirigible aerial bombardment of civilians was on January 19, 1915, in which two German Zeppelins dropped 24 fifty-kilogram (110 pound) high-explosive bombs and ineffective three-kilogram incendiaries on the Eastern England towns of Great Yarmouth, Sheringham, King's Lynn, and the surrounding villages. In all, four people were killed, sixteen injured, and monetary damage was estimated at £7,740 (about US$36,000 at the time). German dirigibles also bombed Liepaja in Latvia on the Eastern Front in January, 1915.
There were a further nineteen raids in 1915, in which 37 tons of bombs were dropped, killing 181 people and injuring 455. Raids continued in 1916. London was accidentally bombed in May, and, in July, the Kaiser allowed directed raids against urban centers. There were 23 airship raids in 1916, in which 125 tons of ordnance were dropped, killing 293 people and injuring 691. Gradually British air defenses improved. In 1917 and 1918, there were only 11 Zeppelin raids against England, and the final raid occurred on August 5, 1918, which resulted in the death of KK Peter Strasser, commander of the German Naval Airship Department. By the end of the war, 51 raids had been undertaken, in which 5,806 bombs were dropped, killing 557 people and injuring 1,358. The Zeppelin raids were complemented by the Gotha bomber, which was the first heavier-than-air bomber to be used for strategic bombing. It has been argued that the raids were effective far beyond the material damage caused, in diverting and hampering wartime production, and diverting twelve squadrons and over 10,000 men to air defenses.
The French army on June 15, 1915 attacked the German town of Karlsruhe, killing 29 civilians and wounding 58. Further raids followed until the Armistice in 1918. In a raid in the afterboon of June 22, 1916 the pilots used outdated maps and bombed the location of the abandoned railway station, where a circus tent was placed, killing 120 persons, most of them children.
In contrast, the British launched their own form of strategic bombing. At the start of the war, there were attacks by bombers of the Royal Navy Air Service (RNAS) against the Zeppelin production lines and their sheds at Cologne and Dusseldorf on September 22 and October 8, 1914. In late 1915, the order was given for attacks on German industrial targets and the 41st Wing was formed from units of the RNAS and Royal Flying Corps. The RNAS took to strategic bombing in bigger way than the RFC who were focussed on supporting the infantry actions of the Western Front. At first the RNAS attacked the German submarines in their moorings then steelworks further in targeting the origin of the submarines themselves.
In early 1918 they operated their "round the clock" bombing raid; with lighter bombs attacking the town of Trier by day and large HP O/400s attacking by night. In April 1918, the Independent Force was created, an expanded bombing group that by the end of the war had aircraft that could reach Berlin but were never used.
Following the war, the concept of strategic bombing developed. The calculations which were performed on the number of dead to the weight of bombs dropped would have a profound effect on the attitudes of the British authorities and population in the interwar years, because as bombers became larger it was fully expected that deaths from aerial bombardment would approach those anticipated in the Cold War from the use of nuclear weapons. The fear of aerial attack on such a scale was one of the fundamental driving forces of British appeasement in the 1930s.
In Europe, the air power prophet General Giulio Douhet asserted the basic principle of strategic bombing was the offensive, and there was no defence against carpet bombing and poison gas attacks. Douhet's apocalyptic predictions found fertile soil in France, Germany, and the United States, where excerpts from his book The Command of the Air (1921) were published. These visions of cities laid waste by bombing also gripped the popular imagination and found expression in novels such as Douhet's The War of 19-- (1930) and H.G. Wells's The Shape of Things to Come (1933) (filmed by Alexander Korda as Things to Come (1936)).
Douhet's proposals were hugely influential amongst airforce enthusiasts, arguing as they did that the bombing air arm was the most important, powerful and invulnerable part of any military. He envisaged future wars as lasting a matter of a few weeks. While each opposing Army and Navy fought an inglorious holding campaign, the respective Air Forces would dismantle their enemies' country, and if one side did not rapidly surrender, both would be so weak after the first few days that the war would effectively cease. Fighter aircraft would be relegated to spotting patrols, but would be essentially powerless to resist the mighty bombers. In support of this theory he argued for targetting of the civilian population as much as any military target, since a nation's morale was as important a resource as its weapons. Paradoxically, he suggested that this would actually reduce total casualties, since "The time would soon come when, to put an end to horror and suffering, the people themselves, driven by the instinct of self-preservation, would rise up and demand an end to the war...". As a result of Douhet's proposals airforces allocated greater resources to their bomber squadrons than to their fighters, and the 'dashing young pilots' promoted in propaganda of the time were invariably bomber pilots.
Pre-war planners, on the whole, vastly overestimated the damage bombers could do, and underestimated the resilience of civilian populations. The speed and altitude of modern bombers, and the difficulty of hitting a target while under attack from improved ground fire and fighters which had yet to be built was not appreciated. Jingoistic national pride played a major role: for example, at a time when Germany was still disarmed and France was Britain's only European rival, Trenchard boasted, "the French in a bombing duel would probably squeal before we did". At the time, the expectation was any new war would be brief and very savage. A British Cabinet planning document in 1938 predicted that, if war with Germany broke out, 35% of British homes would be hit by bombs in the first three weeks. (This type of expectation should be kept in mind when considering the conduct of the European leaders who appeased Hitler in the late 1930s.)
Douhet's theories were tested at Guernica and Guangzhou, which produced international outrage, but not the surrender of the nation that was bombed. They were more successful in Mesopotamia (modern-day Iraq) where RAF bombers used conventional bombs, gas bombs, and strafed civilian populations identified as engaging in guerrilla uprisings. Arthur Harris, a young RAF squadron commander (later nicknamed "Bomber"), reported after a mission in 1924, "The Arab and Kurd now know what real bombing means, in casualties and damage. They know that within 45 minutes a full-sized village can be practically wiped out and a third of its inhabitants killed or injured. Bombing as a military strategy proved to be an effective and efficient way for the British to police their Middle East protectorates in the 1920s. Fewer men were required as compared to ground forces.
The strategic bombing conducted in World War II was unlike anything the world had seen before. The campaigns conducted in Europe, in China and at the end of the war over Japan, could involve thousands of aircraft dropping tens of thousands of tons of munitions over a single city.
Strategic-bombing campaigns were conducted in Europe and Asia. The Germans and Japanese made use of mostly twin-engined bombers with a payload of approximately one ton, and never produced larger craft to any great extent. By comparison, the British and Americans (who started the war with similarly-sized bombers and a few larger designs) developed their strategic force as one based upon much larger four-engined bombers for their strategic campaigns. The payload carried by these planes ranged from 2.7 tons for the B-17 Flying Fortress, to 8 tons for the Avro Lancaster and 9 tons for the B-29 Superfortress, with some specialty aircraft, such as the 'Special B' Avro Lancaster carrying an 11-ton (9,979 kg) Grand Slam bomb.
During the first year of the war in Europe, strategic bombing was developed through trial and error. The Luftwaffe had been attacking both civilian and military targets from the very first day of the war when Germany invaded Poland on 1 September 1939. A strategic bombing campaign was launched to break British morale and achieve a peace agreement after the Luftwaffe was unable to defeat the RAF in the air, and the proposed invasion of Great Britain had to be dropped. Initially, the raids took place in daylight, then changed to night bombing attacks when losses became unsustainable. The RAF, initially espousing a precision-bombing doctrine, also switched to night bombing due to excessive losses. After the Butt Report was released in September, 1941, proved the inadequacy of Bomber Command training and equipment to carry it out, the RAF adopted a area-attack strategy attempting to break German civilian morale. The United States Army Air Forces adopted a policy of daylight precision bombing for greater accuracy as, for example, during the Schweinfurt raids. That doctrine, which included the fallacious theory that bombers could adequately defend themselves against air attack with their own armament, entailed much higher American losses until long-range fighter escorts became available.
Strategic bombing was initially a way of taking the war into Europe while Allied ground forces were no closer to fighting Germans there than North Africa. Between them, the Allied air forces claimed to be able to bomb around the clock. In fact, few targets were ever hit by British and American forces the same day, the strategic isolation of Normandy on D-Day and the the bombing of Dresden in February, 1945 being exceptions rather than the rule. There were generally no coordinated plans for "around the clock" bombing of any target.
Even single missions have been considered to constitute strategic bombing. The British bombing of Peenemünde was such an event, as was the bombing of the Ruhr dams. The Peenemünde mission delayed Nazi Germany's V-2 program enough it did not become a factor in the outcome of the war.
Strategic bombing in Europe never reached the decisive completeness the American campaign against Japan achieved, helped in part by the fragility of Japanese housing, which was particularly vulnerable to firebombing through the use of incendiary bombs. The destruction of German infrastructure became apparent, but the Allied campaign against Germany only really succeeded when the Allies began targeting oil refineries and transportation in the last year of the war. At the same time, strategic bombing of Germany was used as a morale booster for the Allies in the period before the land war resumed in Western Europe.
If the Imperial Japanese Navy Air Service and the Imperial Japanese Army Air Service frequently used strategic bombing over large Chinese cities such as Shanghai, Guangzhou, Nanjing, and Chongqing, in the Pacific theatre, organized strategic bombing on a large scale by the Japanese seldom occurred. The Japanese military in most places advanced quickly enough that a strategic bombing campaign was unnecessary. In those places where it was required, the smaller Japanese bombers (in comparison to British and American types) did not carry a bombload sufficient to inflict the sort of damage regularly occurring at that point in the war in Europe, or later in Japan.
The development of the B-29 gave the United States a bomber with sufficient range to reach the Japanese Home Islands from the safety of American bases in the Pacific or Western China. The capture of the Japanese island of Iwo Jima further enhanced the capabilities that the Americans possessed in their strategic bombing campaign. Conventional bombs and incendiary bombs were used against Japan to devastating effect.
In the Vietnam war, the strategic bombing of North Vietnam in Operation Rolling Thunder could have been more extensive, but fear by the Johnson Administration of the entry of China into the war (and misapprehension of the nature and technique of strategic bombing) led to restrictions on the selection of targets, as well as only a gradual escalation of intensity. The aim of the bombing campaign was to demoralize the North Vietnamese, damage their economy, and reduce their capacity to support the war in the hope that they would negotiate for peace, but it failed to have those effects. The Nixon Administration continued this sort of limited strategic bombing during the two Operation Linebacker campaigns. Images such as that of Kim Phuc Phan Thi (although this incident was the result of close air support rather than strategic bombing) disturbed the American public enough to demand a stop to the campaign.
Due to this, and the ineffectiveness of carpet bombing (partly because of a lack of identifiable targets), new precision weapons were developed. The new weapons allowed more effective and efficient bombing with reduced civilian casualties. High civilian casualties had always been the hallmark of strategic bombing, but later in the Cold War, this began to change.
The Israeli Air Force used strategic bombing during its brief but intense wars with its neighbors during the Six Day and Yom Kippur wars. Strategic bombing was entering a new phase of high-intensity attacks, specifically targeting factories taking years and millions of dollars to build.