Death from the Sky: Who Invented Terror Bombing?

Hayao Miyazaki interpreted the Caproni Ca.60 Transaereo, built in Italy in 1921, in his 2013 film The Wind Rises. The prototype crashed on its second flight and was never built as an operational plane. However, it was an evident attempt to build large bombers to be used for the extermination of civilians according to the doctrine proposed by Giulio Douhet in his famous 1921 book, “The Command of the Air.”

Giulio Douhet (1869-1930) has a square dedicated to him in Rome, and his house in Roma has a plate on the external wall describing him as “the first who theorized the strategic use of the air force” (not true). He is famous for his book Il Dominio dell’Aria (The Command of the Air, 1921), in which he proposed that wars could be won by aiming bombers directly at the civilian population and killing as many people as possible.

Douhet never had a chance to put his ideas into practice himself, but what he wrote is enough to say that he was a morally sick person, a dangerous terrorist, and an enemy of humankind. But these character traits apparently led to success in Douhet’s time, just as they do today.

The idea of killing people from above has an aura of divine punishment that makes it irresistible for rulers and military planners. In ancient times, it was a hobby that only Gods and semi-divine beings could engage in. Things changed when people started developing flying machines. The first science-based ideas on how to make such a machine goes back to the work of Francesco Lana de Terzi, an Italian Jesuit active in the late 17^th century. He not only conceived the first lighter-than-air flying device but also the idea that it could be used for military purposes, hurling iron weights and bombs on cities.

The first mechanical devices that could actually fly were the hot-air balloons developed by the Montgolfier brothers in France in the late 18th century. These balloons could take people up to several thousand meters in the air, but their lack of maneuverability made them poor as bombers. Hydrogen balloons (and, later, helium ones) had a much larger lift and could fly for longer times. The first “airships” (also called “blimps”) were fitted with several hydrogen balloons in an elongated container that was pushed by onboard engines and propellers.

We must wait for World War One to see a military use of airships when all the major powers tested them as bombers. They were impressive-looking weapons but never had a real impact. Navigation, target selection, and bomb-aiming proved to be difficult. Then, effective countermeasures based on artillery and fighter planes were rapidly developed. The damage done by airships over the course of the war was minimal, and their use was abandoned before the war ended.

In parallel with airships, airplanes started being developed at the beginning of the 20^th century. After the pioneering flight of the Wright brothers in 1903, the first bombing raid in history was just eight years later. On November 1, 1911, during the Italo-Turkish War, Italian pilot Giulio Gavotti dropped four grenades on the city of Ain Zara in Libya from his Taube monoplane. These grenades had no effect on the course of the war, but it is reported that several civilians were killed. It was one of those moments that opened completely new perspectives in history.

Just a few years after that first bombing raid, World War 1 started, and planes rapidly became a weapon utilized by all combatants. Unlike the slow and clumsy airships, planes turned out to be effective weapons and there soon ensued a discussion on their role in war. The story is long, and most of it is hidden in obscure publications for use by the military, many of which were never translated into English. A good summary of the discussion can be found in the 1965 book “Guerra Agli Inermi” (“War on the Helpless”) by Amedeo Mecozzi (1892-1971), an Italian military pilot and later strategic theorist.

The first theorizing of aerial war was not done by Dohuet, as it is often wrongly claimed. A French author and aviation pioneer did it, Clément Ader (1841-1925). In the late 19th century, he built steam-powered planes that never really flew, although they could bump up and down a little. Despite the failure of his prototypes, he didn’t lack imagination and he was already writing about military aviation in 1890. In 1909, he published the book “L'Aviation Militaire,” which went through 10 editions in the five years before the First World War. Ader has the distinction of having been the first to conceive that an air force would be composed of three kinds of planes: reconnaissance (éclaireurs), bombardment (“torpilleurs”), and aerial fighting (“avions de ligne”). Among other things, Ader was the first to imagine “navires porte avions,” aircraft carriers.

Ader also discussed how the Air Force would be used in war. He understood that the domain of the air would be a fundamental advantage in war, and he described several scenarios in which opposing air forces would fight each other and then could be used to attack the ground forces of the enemy. He describes as an effective strategy the use of the air force to bomb the enemy’s civilian population, even though he said it was cruel and inhuman.

Giulio Douhet built his ideas on aviation on Ader’s ones. He described his view in detail in his 1921 book “Il Dominio dell’Aria.” Seen from our viewpoint, more than a century later, Douhet’s ideas look naïve, impractical, and counterproductive. His basic idea was that stopping a fleet of bombers was simply impossible. A view that was echoed in 1932 by Stanley Baldwin, prime minister of the UK, in terms of the famous quote, "The bomber will always get through." That has never been true, but once you accept this statement, you can propose that a war would be reduced to a sort of tit-for-tat game in which each side’s bombers would systematically destroy the enemy cities.

“Beware of the man with a single solution to all problems” is a maxim we can apply to Douhet. It is a manifestation of the rule that for every problem, there exists a simple, straightforward, and wrong solution. But Douhet was smart enough to pack his proposal as an improvement over the terrible carnage that World War 1 had been, promising that razing cities down would be brutal but short. In other words, he was one of those prophets who promised that the new war would end all wars.

Douhet provided some calculations based on a carpet-bombing model that reminds painting a wall. Assume that a certain number of bombers can destroy a fixed area of territory daily. Then, you can calculate how long it would take and how many bombers are needed to destroy a certain fraction of the urbanized enemy territory. The problems of aiming the bombs, the enemy’s flak, the effects of clouds and bad weather were totally ignored. Douhet’s final result was that some 10,000 bombers would be needed to raze to the ground all the cities of a whole European country. After some cost calculations, Douhet concluded that the government shouldn’t waste money on conventional ground forces and not even fighter planes. The bombers would be all that was needed to wage a war and win it. Mecozzi correctly describes this approach as a “comics-like absurdity.”

What made Douhet develop such mad ideas? We can perhaps propose that he was trying to atone for his behavior during WWI when he refused to take his regiment to fight on the frontline (p 99 of Douhet’s diary, as reported by Mecozzi on p 189 of his book). Or perhaps it was because of Douhet’s friendship with Gianni Caproni, owner of a company that manufactured bombers—a friendship that surely had financial rewards. Gianni Caproni was probably inspired by Douhet when he built a huge experimental plane in 1921, the same year when Douhet’s book appeared. The Caproni Ca.60 Transaereo was a nine-wing monstrosity that was supposed to be a passenger plane, but surely it could be transformed into a bomber. It crashed on its second test flight and was never rebuilt, but it was an ominous beginning for the diffusion of Dohuet’s ideas.

Naïve as much as you want, it is also true that Douhet’s ideas were extensively tested during the more than one hundred years of history after their publication. WW1 saw the first attempts of terror bombing against civilians from the air, but the planes (and, initially, the airships) available were not powerful nor effective enough to have a major effect. It was only several years later that a serious extermination of civilians could be obtained by aerial bombardment. It was with the famous Guernica bombing during the Spanish Civil War in 1937, carried out by the German Luftwaffe's Condor Legion and the Italian Aviazione Legionaria under the code name of “Operation Rügen.” The number of estimated casualties in Guernica varies from a few hundred to about 1,500 people. It was not large compared to later bombing campaigns, but the impression on the world was strong. You may remember Picasso’s famous painting “Guernica,” which was inspired by the bombardment. The raid was later justified by saying that it aimed at destroying bridges and roads, but it is hard to think that those who carried out the operation didn’t know that they were bombing a town inhabited by civilians.

Guernica was the harbinger of things to come, and Douhet’s ideas were to be fully tested during World War Two. After the defeat of France, the Allies and the Axis forces couldn’t fight each other on the ground because of the barrier of the English Channel. So, both tried to use terror bombing to force the other side to surrender. The German attempt was a complete failure; the “Battle of Britain” lasted for just a few months, from July to October 1940. The German losses were appalling, and the damage done remained limited. More than all, the German bombs never broke British morale. Remarkably, though, despite the failure, the Germans managed to keep their bombers engaged in a low-level bombing campaign aimed at British civilians for the remainder of the war. Such is the fascination of terror bombing.

On the other side, the Allied terror campaign against Germany was much more massive and destructive. The Allies aimed directly at the German cities and soon took as their objective to destroy them completely by igniting “firestorms.” That was a new and unexpected factor in aerial bombing. For a sufficiently intense bombing concentration and the use of incendiary bombs, cities could catch fire and burn to the ground by themselves almost completely, especially in the presence of strong wind.

The first firestorm occurred in Hamburg from July 24 to 30, 1943, due to a massive bombing campaign by the British Royal Air Force (RAF), prophetically termed “Operation Gomorrah.” Incendiary devices dropped from the British planes created a firestorm that destroyed large parts of Hamburg, including residential areas. The number of civilians killed is estimated to be around 40,000.

Both the Germans and the Allies were impressed by this result, and the Allies tried hard to reproduce it in other German cities, especially Berlin. But they succeeded only one more time, in the case of Dresden, most of which was razed to the ground by a firestorm generated by the combined British and US bombing on February 13-15, 1945. The story is told in detail by Kurt Vonnegut, then an Allied prisoner in Dresden, in his novel “Slaughterhouse Five.” (1969).

It is remarkable how the Allied command focused on terror bombing against civilians when it must have been soon clear that the objective of demoralizing the enemy population simply didn’t work. There were other methods to use bombers, and one creative idea was to destroy German ball-bearing factories. That would have literally ground to a halt all German military vehicles and made them unable to continue the war. It was tried with the “Second Schweinfurt raid” operation, which took place on October 14, 1943, when the American bombers from the Eighth Air Force targeted the ball-bearing factories in Schweinfurt. This raid was partly successful, but it became known as "Black Thursday" due to the heavy losses suffered by the bomber fleet. That led the Allies to abandon these targeted operations and focus on bombing less heavily defended cities. We cannot say whether that was directly inspired by Douhet’s book, which was published in English in 1942, but it might be.

We may wonder whether WW2 could have ended in 1943 had the Allies insisted on attacking the vital centers of the German industry. Surely, the costs of a few targeted raids couldn’t be as high as continuing the bombing campaign for two more full years. But that didn’t happen, as perhaps should have been expected considering the mentality of the leaders at that time. We can have a glimpse of how they reasoned from the book “Disturbing the Universe” (1979) by Freeman Dyson who, during the war, was a young mathematician working for the British Bomber Command. Dyson described his situation as working for “An organization dedicated to killing people and doing the job badly.”

Apparently, the leaders of Bomber Command were interested mainly in their personal prestige and career, not necessarily in obtaining a rapid victory. Among other things, they refused to consider the sensible option of stripping down bombers of the heavy machine guns they carried, found to be scarcely effective against enemy action. Lighter bombers could be faster, carry a higher payload, and need a smaller crew, hence reducing human losses in case of being hit or downed. But the leaders were stuck in a vision that saw bombers as “flying fortresses” (an idea proposed first by Douhet), undoubtedly more spectacular to show to the public. Then, the performance of the bombing operation was measured mostly in terms of the number of bombs dropped compared to the planes lost. Once that was established, it was obvious that the bomber fleet should have been directed against the least defended targets, which nevertheless provided spectacular results: residential areas. Whether that affected the war as a whole was secondary.

On the other side of Eurasia, Japan and the US faced each other on the ground only on small islands, so the US engaged in a massive bombing campaign against Japanese cities. They succeeded twice in generating firestorms; once in Tokyo on March 9-10, 1945, and then in Kobe just one week later. In both cases, the Japanese wooden houses burned like matches, and the civilian casualties were even larger than in Germany. The US Air Force finished the job with the two nuclear warheads dropped on the cities of Hiroshima and Nagasaki in August 1945. There are some reports https://jacobin.com/2023/08/atomic-nuclear-bomb-world-war-ii-soviet-japan-military-industrial-complex-lies that, initially, nuclear bombs were thought as tactical weapons to be used against military targets in support of the land invasion of Japan. Instead, it was decided to use them as terror weapons against civilian targets. Was it Douhet’s ghost haunting the US high command? We’ll never know that.

The Japanese didn’t attempt to bomb American civilians, but it doesn’t seem that it was because of moral concerns. More likely, they didn’t have the resources necessary to send bombers to hit the United States continental territory. Yet, they tried their best to engage in terror bombing by directing balloon bombs toward the United States mainland with the idea of starting forest fires. It was the ultimate wanton destruction that not only didn’t consider the difference between civilians and combatants but not even between human beings and wild animals. In any case, these balloon bombs didn’t cause significant damage to anything.

Spectacular as they were, the allied bombing campaigns didn’t work the way Douhet thought they would. Despite being bombed around the clock, the Germans fought all the way to the end. The Japanese also doggedly continued their resistance, and even after having been nuked, they were ready to fight the invaders using sharpened bamboo sticks had they they attacked Japan with a ground force. The Japanese were saved by a direct intervention of the Tenno, the Emperor, who forced the government to surrender to the Americans. Something similar happened two years before in Italy, where a direct intervention by the King of Italy ousted dictator Mussolini and forced the the government to surrender. However, a significant fraction of Italians refused to obey and continued to fight the Allied forces until the end of the war. It was the exact opposite of what Douhet had thought would happen: the population was not demoralized and wanted to continue fighting. It was the leaders who decided that they had no reason to fight to the end and then be hanged by the winners.

After WW2 was over, the world hasn’t seen again, so far, an all-out military confrontation between two comparably armed powers, although the recent war in Ukraine may evolve exactly into that. It may have been because of the fact that the major powers were all equipped with nuclear weapons, and no one wanted to unleash the “MAD” (mutually assured destruction) on each other. However, aerial bombing remains a favorite strategy of Western governments, although used only against adversaries that could not retaliate in kind. With a large unbalance of forces, bombing often turned out to be effective in forcing the target country to surrender, as happened with Serbia in 1999, or to kill country leaders who refused to surrender, as happened with Muammar al-Gaddafi in Libya in 2011. It didn’t always work, not even with the support of ground troops, as was the case of Afghanistan, abandoned by the Western troops in 2022 after 20 years of unsuccessful attempts to control the country.

Overall, we can say that the world has never seen a case in which we saw a confirmation of Douhet’s idea that aerial bombing directed against civilians is the one and only valid strategy to win wars. Yet, things always change with the development of new technologies, and it may be that the development of low-cost autonomous military drones will change war strategies again and perhaps give new life to the idea that killing innocent people is a good way to win wars.

On this point, a thread links Douhet’s ideas to Konrad Lorenz’s ones. Lorenz’s intuition was that human cruelty resulted from having developed technologies that made killing cheap and easy. A single human being can kill another one with his/her bare hands, but it is a messy, hard, and uncertain task. Simple stone or metal weapons make the task much faster and easier, and this is the probable reason for the homicidal streak that has characterized human history during the past few thousand years. The question here is whether further technological developments can bring the cost of killing people to even lower levels. That was Douhet’s intuition: according to his view, bombers were so cheap and effective that they would be the only weapon needed in war. It wasn’t true at his time and is still not true today for human piloted bombers; expensive and delicate, an easy target for missiles or even simple anti-aircraft artillery. However, unmanned aerial vehicles may change everything again. They might become the wonder weapon that will “always get through,” as Douhet and his followers were thinking.

Unmanned “suicide drones” were tried for the first time by the Germans during the last phase of WW2 to attack British territory. They were called Vergeltungswaffen, “revenge weapons,” and two kinds were produced: the V-1, a jet-powered plane, and the V-2, a full-fledged missile flying in a parabolic trajectory. Historians tend to agree that the Vergeltungswaffen were a counterproductive effort. They were inaccurate, consumed a lot of precious resources, and their main effect was to enrage the British population. Only occasionally, they were used as tactical weapons. A V1 was launched at the Remagen Bridge, taken by the Allies in 1945, the first Allied bridgehead into Germany. The V1 missed the bridge.

Today, however, drones are much more precise and controllable, way superior to anything Germany could put together in haste while being defeated in WW2. It is always difficult to imagine the effects of a new technology when it has not yet been deployed on a large scale. I tried to imagine that in a chapter I wrote as part of Jorgen Randers’ book “2052.” (2012). In it, I argued that military drones might be seen as a good thing (as much as weapons can be, of course!). Perhaps they would fight each other, leaving human beings in peace. More than 10 years later, drones are becoming a fundamental military factor and there are at least some hints that my view was correct.

A preview of the things to come arrives from the attacks carried out in 2019 against the Saudi oil facilities by a swarm of drones launched from Yemen. Remarkably, no human casualties were reported. It was hardware against hardware: machines destroying other machines. A similar tit-for-tat exchange took place in April 2024, when Israel and Iran attacked each other using mainly drones. In neither case were human casualties reported.

Unfortunately, the robot vs. robot fight remains an exception rather than the rule. In Ukraine, drones are used mostly as long-range artillery, not unlike the situation in the trenches of WWI. In Gaza, then, drones seem to be used directly as a terror weapon against civilians. We are seeing the actual development of "slaughterbots," minimalistic drones that have only one purpose: killing people.

The only sure thing is that technology changes the world not so much because of what technology can do but because of what people use the technology for. And history tells us that if people are, correctly, opposed to being slaughtered by bombing, they are happy, actually enthusiastic, whenever the slaughtered ones are other ethnic groups or the citizens of another state. The problem goes back to an abused quote that says, “guns don’t kill people, people do.” We can transform it into the equivalent “drones don’t kill people, people program drones to kill people.” So, the problem is not so much drones but people. And there seems to be truly little we can do about that.