In my warfare survey, I have a visual gag where for a week and a half after our WWI lecture, every lecture begins with the same slide showing an aerial photograph (Wiki) of the parallel trenches of the First World War because so much of the apparatus of modern warfare exists as a response, a desperate need to never, ever do the trench stalemate again. And that’s where our story starts.

Fighting aircraft, as a technology in WWI, were only in their very infancy. On the one hand the difference between the flimsy, unarmed artillery scout planes of the war’s early days and the purpose-built bombers and fighters of the war’s end was dramatic. On the other hand the platforms available at the end of the war remained very limited. Once again we can use a late-war bomber like the Farman F.50 – introduced too late to actually do much fighting in WWI – as an example of the best that could be done. It has a range of 260 miles – too short to reach deep into enemy country – and a bomb load of just 704lbs. Worse yet it was slow and couldn’t fly very high, making it quite vulnerable. It is no surprise that bombers like this didn’t break the trench stalemate in WWI or win the war.

However, anyone paying attention could already see that these key characteristics – range, speed, ceiling and the all-important bomb-load – were increasing rapidly. And while the politicians of the 1920s often embraced the assumption that the War to End All Wars had in fact banished the scourge of war from the Earth – or at the very least, from the corner of it they inhabited such that war would now merely be a thing they inflicted on other, poorer, less technologically advanced peoples – the military establishment did not. European peace had always been temporary; the Peace of Westphalia (1648) and the Congress of Vienna (1815) had not ended war in Europe, so why would the Treaty of Versailles (1919)? There had always been another war and they were going to plan for it! And they were going to plan in the sure knowledge that the bombers the next war would be fought with would be much larger, faster, longer ranged and more powerful than the bombers they knew.

One of those interwar theorists was Giulio Douhet (1869-1930), an Italian who had served during the First World War. Douhet wasn’t the only bomber advocate or even the most influential at the time – in part because Italy was singularly unprepared to actually capitalize on the bomber as a machine, given that it was woefully under-industrialized and bomber-warfare was perhaps the most industrial sort of warfare on offer at the time (short of naval warfare) – but his writings exemplify a lot of the thinking at the time, particularly The Command of the Air (1921). But figures like Hugh Trenchard in Britain or Billy Mitchell in the United States were driving similar arguments, with similar technological and institutional implications. But first, we need to get the ideas.

Like many theorists at the time, Douhet was thinking about how to avoid a repeat of the trench stalemate, which as you may recall was particularly bad for Italy. For Douhet, there was a geometry to this problem; land warfare was two dimensional and thus it was possible to simply block armies. But aircraft – specifically bombers – could move in three dimensions; the sky was not merely larger than the land but massively so as a product of the square-cube law. To stop a bomber, the enemy must find the bomber and in such an enormous space finding the bomber would be next to impossible, especially as flight ceilings increased. In Britain, Stanley Baldwin summed up this vision by famously quipping, “no power on earth can protect the man in the street from being bombed. Whatever people may tell him, the bomber will always get through.” And technology seemed to be moving this way as the possibility for long-range aircraft carrying heavy loads and high altitudes became more and more a reality in the 1920s and early 1930s.

Consequently, Douhet assumed there could be no effective defense against fleets of bombers (and thus little point in investing in air defenses or fighters to stop them). Rather than wasting time on the heavily entrenched front lines, stuck in the stalemate, they could fly over the stalemate to attack the enemy directly. In this case, Douhet imagined these bombers would target – with a mix of explosive, incendiary and poison gas munitions) the “peacetime industrial and commercial establishment; important buildings, private and public; transportation arteries and centers; and certain designated areas of civilian population”. This onslaught would in turn be so severe that the populace would force its government to make peace to make the bombing stop. Douhet went so far as to predict (in 1928) that just 300 tons of bombs dropped on civilian centers could end a war in a month; in The War of 19– he offered a scenario where in a renewed war between Germany and France where the latter surrendered under bombing pressure before it could even mobilize. Douhet imagined this, somewhat counterintuitively, as a more humane form of war: while the entire effort would be aimed at butchering as many civilians as possible, he thought doing so would end wars quickly and thus result in less death.

Clever ideas to save lives by killing more people are surprisingly common and unsurprisingly rarely turn out to work.

Bret Devereaux, “Collections: Strategic Airpower 101”, A Collection of Unmitigated Pedantry, 2022-10-21.