What about, instead of going through the trench lines, we went over them?

There are two directions to take airpower here: tactical and strategic. One wasn’t ready then (but would be by WWII), the other still hasn’t managed to accomplish its stated objectives yet, but continues to over-promise and under-deliver results.

Let’s deal with tactical airpower first. The first function aircraft were put to in WWI was reconnaissance. In 1914, that might mean locating the enemy in a fast-moving battlefield, but as soon as the trench stalemate set in, reconnaissance mostly meant identifying enemy buildups along the line and – still more importantly – serving as spotters for artillery. It wasn’t a huge cognitive leap to go from having aircraft which identified targets for the artillery to thinking that the aircraft could be the artillery. But as with tanks, the technical limitations of the platforms in use meant that actually meaningful close air support was still two decades away when the war ended. The rapid development of aircraft in these early days means that there is a truly bewildering array of aircraft designs in use during the war, but the Farman F.50 is a good sample for what the most advanced bombers in common use looked like towards the war’s end. It carried a maximum of eight 44kg bombs (352kg) under the wings, which were dropped unguided. With a maximum speed of less than 100mph and a service ceiling under 5000m, it was also an extremely vulnerable platform: fragile, slow and with a relatively low flight ceiling. The French mainly used bombers at night for this reason.

But how much airpower does it take to really move a division out of position? In 1944, at the start of Operation Cobra as part of the Normandy breakout, it was necessary for US forces to move the powerful armored division Panzer Lehr out of its prepared positions outside of St. Lo. Over the course of an hour and a half, the U.S. Eighth Air Force hit Panzer Lehr with approximately three thousand aircraft, including 1,800 heavy bombers (each of which might have had bomb-loads of c. 2-3,500kg; the attack would have been the equivalent of about 13,000 Farman F.50s (of which only a hundred or so were built!)). By this point, even medium bombers carried bomb loads in the thousands of pounds, like the B-25 Mitchell medium bomber, with a bomb load of 3000lbs (1360kg). This was followed by a hurricane artillery barrage! Despite this almost absurdly awesome amount of firepower (which, to be clear, inflicted tremendous damage; by the end of Operation Cobra, Panzer Lehr – the heaviest and most powerful Panzer division in the west – had effectively ceased to exist), Panzer Lehr, badly weakened was still very capable of resisting and had to be pushed out of position by ground attack over the next three days.

Needless to say, nothing on offer in 1918 or for a decade or more after, was prepared to offer that kind of offensive potential from the air. That kind of assault would have required many thousands of aircraft with capabilities far exceeding what even the best late-war WWI bombers could do. Once again, while close air support doctrine was developed with one eye on the trench stalemate and the role airpower could play in facilitating a breakthrough and restoring maneuver (either by blasting the breakthrough or – as in Soviet Deep Battle doctrine – engaging enemy rear echelon units to bog down reinforcements). But the technology wasn’t anywhere near the decisive point by 1918. Instead, the most important thing aircraft could do was spot for the artillery, which is mostly what aircraft continued to do, even in late 1918.

But that’s tactical bombing against military targets. What about strategic bombing against civilian targets?

The first efforts at strategic bombing were made in WWI, though once again the technology wasn’t ready. The range for fixed-wing aircraft was still very limited; the aforementioned Farman F.50 had a range of only 420km, nowhere near enough to really bring entire countries under the threat of bombing. Dirigibles – zeppelins – could manage much longer ranges and the Germans did attempt to bomb British cities with them starting in 1915. The problem was that once aircraft powerful enough to climb to the zeppelin’s altitude were developed, the slow and fragile zeppelins were sitting ducks: lighter than air airships could hardly be armored, after all. Moreover, the bomb loads of zeppelins had always been far too low to make effective strategic bombing possible beyond the initial shock of it.

What no one could have known in WWI was not merely that the technology for effective conventional strategic bombing wasn’t ready, but that it would probably never be ready. Interwar air-power theorists, seeing the potential of strategic airpower to bypass the trench stalemate by flying over it began to try to work out how this would be done. Giulio Douhet (1869-1930) argued that future wars would be fought and won in the air, with fleets of bombers using high explosives and chemical weapons to massacre enemy civilian centers, until civilians forced their governments to surrender. Douhet was not alone; his vision of airpower was shared, for instance, by the “father of the RAF”, Hugh Trenchard (1873-1956).

This concept, “morale bombing” as it is sometimes called, probably deserves its own post discussing its failures. But in brief, the concept was tested, with far larger amounts of bombs than Douhet or any other interwar theorist could have ever dreamed of, during WWII. The argument by air theorists that high altitude bombers could not be stopped was proved false when the British did exactly this, stopping German bombers over Britain in 1940. Moreover, terror bombing against civilian targets in Britain didn’t lead to surrender, but hardened resolve. Likewise, “morale” bombing against German targets by the allies didn’t lead to surrender, but hardened resolve. Later efforts to demoralize the North Vietnamese through a American bombing campaign in the Vietnam War didn’t lead to surrender, but hardened resolve. More recent efforts to demoralize or destroy terrorists and the Taliban through the use of airpower hasn’t lead to surrender, but rather hardened resolve. Likewise, efforts by the Syrian Regime to defeat various opposition groups in Syria through the use of chemical weapon-based terror bombing didn’t lead to surrender (siege-and-starve tactics did), but hardened resolve.

It turns out the fundamental premise of the entire idea of morale bombing – that being bombed will make people want to stop fighting – was flawed. Morale bombing has been, depending on how hard you squint at the US air campaign over Japan in WWII (including the use of nuclear weapons) successful either once (out of many attempts) or never. In most cases, the sustained bombing of civilian centers has been shown to increase a population’s willingness to resist, making the strategy worse than useless.

The case for strategic bombing against industrial targets is marginally better, but only marginally. While airpower advocates, particularly in the United States promised throughout WWII that bombing campaigns against German industry could lead to the collapse of the German war machine, in the end many historians posit that the real achievement of the campaign was to lure the Luftwaffe into the air where it could be destroyed, thus denying the German army of air cover and close air support, particularly on the Eastern Front. Some diminution of German industrial capabilities was accomplished (though it is not clear that this ever approached the vast resources poured into producing the large numbers of extremely expensive bombers used to do it, though the allies had such an industrial advantage over Germany, forcing the Germans to fight in expensive ways in the sky was a winning trade anyway), but the collapse of German industry never happened. As Richard Overy notes, German industrial output continued to rise during strategic bombing and only began to fall as a result of the loss of territory on the ground. Needless to say, “strategic bombing can sucker the enemy into wasting their close air support” was not the result that airpower advocates had promised, nor could it have broken the stalemate.

I don’t want to oversimplify the continued debate over the efficacy of strategic airpower here too much so let’s just say that the jury is still very much out as to if strategic airpower works even with modern technology; it certainly wouldn’t have worked with WWI era technology.

Bret Devereaux, “Collections: No Man’s Land, Part II: Breaking the Stalemate”, A Collection of Unmitigated Pedantry, 2021-09-24.