I just finished reading "How the War was Won" by Phillips Payson O'Brien. I think I first heard about this during an interview with Paul Krugman, and was sufficiently motivated to pick it up. The book's main thesis is that World War 2 was primarily won by the US and the UK applying overwhelming naval and air power, and not so much as a result of large land battles. The book ended up being more technical and less narrative than I expected: there are a lot of tables and charts, and long paragraphs in which O'Brien rattles off facts like the numbers and prices of pieces of equipment produced by different countries in various years. I'm not complaining: the book is really good, just written a bit differently than I was expecting.
I do appreciate when he tells illustrative stories, which are a smaller part of the book but placed well and generally help reinforce the data-based arguments he primarily focuses on. One example is Saburō Sakai, a very talented Japanese pilot who was wounded in combat, redirected to training new pilots, pressed back into service due to a shortage of experienced pilots, and tried to lead a squadron from the home islands into combat. Bad weather, training and equipment kept them from making it in time for the battle, and many planes were lost along the way. This neatly lines up with O'Brien's arguments about the danger of deployment and the loss of material: throughout the war, and increasingly as it went on, far more equipment was destroyed off the battlefield than on the battlefield.
I think the author is writing to people towards the upper side of the Dunning-Kruger curve, while I'm to the left of that. As an American who has a middling grasp of World War 2 from secondary school and erratic reading as an adult, I tend to associate the war with events like Pearl Harbor, D-Day and Hiroshima. O'Brien isn't so much writing to me: he's writing to address fellow professional historians, who have the view that WW2 was largely decided by fighting on the Eastern Front, particularly battles like Stalingrad and Kursk that caused massive casualties for Germany and the Soviet Union. O'Brien spends quite a bit of time at the start of the book summarizing the arguments and citing experts who disagree with his thesis, which I actually hugely appreciated, as I was personally not very familiar with the dominant thinking. I've read other books (Erik Loomins's "A History of America in Ten Strikes" comes to mind) where I feel like I've wandered into the middle of a long-running argument and I have no idea what people are talking about or why.
It seems like the push for massive investment in air power was mostly driven by the political leaders of the countries (Roosevelt, Churchill, Hitler) and not so much the military establishment, which I thought was interesting, and does line up with other things I've read like Erik Larson's "The Splendid and the Vile." It also makes me think a little of Abraham Lincoln, who didn't have a military background but studied military topics thoroughly and ended up with a better understanding of strategy than many of his generals. Part of this may be the tendency of militaries to fight the last war, applying the lessons of the past instead of anticipating the effects of more recent technological advances. I got the impression from this book that generals and admirals didn't necessarily disbelieve the power of air, but it took outside political pressure to take resources away from existing services and put them towards the new ones. (Of course, many would say that the Air Force learned this lesson too well!)
A crystallizing statement O'Brien makes is something like "The United Kingdom essentially traded expensive equipment for human lives." Throughout the war, the UK lost something like 47,000 members of the RAF, either during offensive and defensive missions or when being targeted by the Luftwaffe. That 47,000 sounds like a huge number, but it was fewer men than the UK lost in the first two days of the Battle of the Somme in World War 1. The UK was fighting for survival: not in the abstract sense of remaining an independent political entity, but in the literal sense of letting the human beings on that island continue to live past the war. So, by building expensive airplanes and bombing factories making tanks, the UK ensured that those tanks wouldn't face British soldiers on the battlefield. Likewise for the US, many pilots and sailors lost their lives attacking merchant shipping in the Pacific, but one result of that was that only a handful of Japanese tanks made it to the Philippines, and most of those were bombed before their first combat, so when American ground troops did land they had a much easier time fighting than they would have otherwise.
I was surprised to learn that Germany had about as many civilians working on aircraft construction as the US did. But Germany produced far fewer planes, mostly because of the hostile conditions generated by the RAF. Germany had to disperse its factories into smaller installations scattered throughout the Reich so any single bombing run would be less catastrophic; later, they moved factories into caves and even hollowed-out mountains. That let production continue, but much more slowly, and less reliably, with far more flaws in the finished aircraft. In contrast, America could build huge, sprawling industrial complexes, organized rationally and optimized for speed, without any concern about the defensibility of their factories.
O'Brien acknowledges that there were many acts of heroism in WW2, but also argues that heroism didn't win the war: the fact that the Allies were able to out-build and out-deploy the Axis won the war. Another crystallizing nugget for me: the Battle of Midway was one of the most consequential engagements of the Pacific Theater, with about 250 Japanese planes destroyed during this battle. And yet, at this time Japan was building approximately 100 planes each day, so this great battle only set them back by about three days. What made far more of an impact were the planes that America denied Japan from even constructing in the first place: by destroying shipments of bauxite and oil while being shipped on the seas, by bombing factories that were assembling planes, by picking off finished planes while they were deploying en route to their forward operating bases. These actions were less exciting and heroic than Midway, but had a far bigger impact in defeating Japan.
For most of the first part of the book O'Brien is persuasive in arguing for the importance of equipment, but he does not look at alternative arguments, about the importance of territory and manpower. He explicitly says at one point that this book doesn't take manpower into account, but I think you do have to consider it if you're arguing that equipment is more important. Conceptually, I can see how one human being in the cockpit of a bomber has more destructive power than one human being holding a rifle, and I can kind of intuit how looking at the armed forces through the lens of expenses versus enrollment is valid. But at the end of the day, you do need a pilot in that plane: in the 1940s they weren't flying themselves.
For most of the book O'Brien kind of erases humans from the picture altogether. This does change more later in the book, as he not only looks at the role of people, but also acknowledging hat they aren't all interchangeable. One great example is Japan: they had many talented pilots early in the war, later on Japan still made a lot of planes (even more than before, as they gained access to bauxite from the Dutch East Indies which allowed them to make more aluminum and thus more planes), but they had considerably fewer experienced pilots, and as a result most of these brand-new planes never even made it to the front. O'Brien doesn't seem to really look at the experience of Allied forces, other than the implicit contrast with the poorly-trained late-war Axis forces.
Turning back to the question of the Eastern Front, O'Brien shows how the Reich was forced to deploy most of its air force on the western front to defend against RAF raids, which significantly lightened the air pressure it could deploy to the Eastern Front. This kept Germany from achieving air superiority during battles like Stalingrad and Kursk, which immensely helped the Soviets. But I think you do need to look at the counter-argument as well: 80% of the German army was fighting on the Eastern front, and if they weren't there, then they would have been available for other operations in places like North Africa, the Middle East, and possibly even the UK. O'Brien does eventually address this question of the significance and utility of ground forces, but not until much later in the book.
Outside of combatants, he does write a little bit about human resources. For example, large numbers of German workers had to be redirected to repairing the damage from "strategic" bombing of industry, which made those workers unavailable for new production. Also, Hitler ordered a large increase in the manufacture of anti-aircraft flak guns, which he thought were more effective than fighter planes; these new guns required large numbers of people redirected from factory work to manning AA guns. Later on, as we get into 1944 O'Brien talks more explicitly about the manpower demands on the German population. Men were being taken from factories and put into military service, which caused a spiraling decline in German production, which further harmed the effectiveness of the military, increasing their losses and requiring still more manpower (which was taken from the factories, and so on and so forth). It took a while to get here, but I did like this zoomed-out look at allocation of human resources between military and industrial roles.
Later on, he gives a strong focus on transportation and maneuvering, which contemporary writing confusingly calls "communication". After D-Day, Germany had divisions earmarked to rush to the French coast to repel the invaders; but even groups stationed in France often couldn't get to the front for nearly a month, due to Allied destruction of railroads and bridges, and aerial bombing during the day forced the movements to move during the (short summer) nights, often on foot or occasionally with nearby vehicles. In the last chapter O'Brien colorfully writes that, while Germany had a large number of well-trained troops with superior land equipment, who in theory should have been able to drive the Allies back to the sea; but without maneuverability, they weren't able to meet their opponents in force, and instead were slowly fed into a meat grinder that slaughtered the Axis soldiers. For me, this finally kind of closes the circle on how air and sea power were more important than land combat in the war: if land units can't maneuver, they are kind of irrelevant to the outcome of the war, even on top of the reduced power land units have from lacking material, ammunition, vehicles, fuel, and other resources they were deprived of by the air and sea war.
I really liked the look at personalities driving strategy in the war. Ernest King, the head of the US Navy, stands out for being particularly obstinate and bull-headed. He single-handed caused disaster at the start of the US entry into the war. King was determined to focus on Japan, while all the other military and political leaders wanted a Germany-first strategy. King also deeply distrusted the British, so he wanted the US Navy to operate independently of them. Because of these biases, King kept a huge naval presence in the Pacific, which in turn allowed German U-Boats to operate directly off the American East Coast, causing enormous losses in shipments of vital war supplies to the UK. There were only six U-Boats operating along the coast, and they had a field day, which they called the "Happy Time."
King refused to bring destroyers back from the Pacific, so the problem wasn't solved until enough new ships were constructed to defend the coast; even then, he directed the majority of new ships to the Pacific. King even brazenly lied to the UK during their conferences, stating that 15% of American force was in the Pacific and needed to be higher, when it was actually more like 80% of the Navy.
But in the end, the Navy did prove extremely effective and were able to accomplish their goals, including the smart "Central Pacific" strategy: instead of the original plan of gradual land battles through New Guinea, the Dutch East Indies, Borneo, Malaysia, Thailand, Burma and China before attacking Japan, the Navy island-hopped to come within range of Japan; because of this, they could cut off all support for the deployed Japanese military forces to the south, and not need to fight them at all.
There are lots of things in this book that are probably well-known to people who have studied World War 2, but are pretty new to me personally. One is the difference between US and UK aims in the war. The US had a very clear plan for action - they wanted to defeat Germany and Japan as quickly as possible - and only a hazy idea of what they wanted after the war, just a general sense of a more peaceful and democratic order. In contrast, the UK had a very clear goal for what they wanted after the war - maintaining the power of the British Empire - and were relatively vague and ambivalent about what actions to take during the war, but always kept that goal in mind. That's a big part of why Churchill was so reluctant to commit to a ground invasion of France, and also why he opposed Roosevelt's suggestions to give India a freer hand.
The Americans were pushing hard for a 1943 invasion of France, while Churchill argued strongly for a Mediterranean mission instead. O'Brien seems to suggest that invading France in 1943 probably would have been better. The Allies did occupy more territory in 1943, but gained no land that was really critical for the outcome of the war against Germany. They managed to destroy a decent amount of German production, but production remained high, peaking in 1944. Ultimately the Normandy beaches were far more strongly fortified in 1944 than they were in 1943, so the delay probably hurt at least as much as it helped.
While the Mediterranean fighting had little influence on the ultimate outcome of the war, the Battle of the Atlantic was very impactful. O'Brien says that, when Admiral Doenitz withdrew his U-Boats from the Atlantic, Germany lost any hope of winning the war. They could still make offensive movements and win battles, but after that time they could no longer deny the production and deployment of enemy war equipment, so it was inevitable that the Allies would succeed. As O'Brien writes, "The Germans would continue to fight for two more years, inflict a huge amount of damage and, at times, mount successful operations - but all it was doing was forestalling the inevitable."
In the course of reading this book, I cam to understand how World War 2 required an entirely different conception of war. One fairly straightforward example is the ability to destroy or divert material outside of traditional combat: instead of blowing up tanks while the tanks are trying to blow up you, you can sink the boat that's carrying the tanks into theater, or bomb the tanks while they're in the maintenance yard, or bomb the factory that's building the tanks, or bomb the railroads carrying iron into the factories. But another conceptual shift was requiring the enemy to build up a certain kind of defense, requiring an investment that diminished their strength in other areas. For example, the Germans directly sunk a lot of cargo in the Atlantic early in the war. Later on America built up the Atlantic fleet, stemmed the losses thanks to their escort system, and eventually drove out the U-Boats. That's all great. But building up the escort fleet was very expensive and took a ton of resources that could have gone into aircraft or other production.
The Allies ended up over-shooting their needs, laying down many more destroyers than ended up actually being needed (remember, this all started due to a mere six U-Boats operating off the coast). This is particularly tricky for ships, since they are so capital-intensive and require such a long lead-time compared to other material, so if you turn off the production faucet at some point you still have years' worth of investments that are just lost. So, while the Allies won the battle of the Atlantic, it was also one of the most effective battles that the Germans waged, in terms of requiring big investments from their adversaries.
There are lots of other examples of seeing the war through the lens of expense and investment rather than casualties and territory. The Allies hammered U-Boat pens for years, and never damaged any of them because they were so well constructed. This seems like a sort of victory for the Reich, as they denied the Allies their war goal. But, the pens required massive amounts of concrete, and the concrete used there was concrete not used in beachhead bunkers or factory fortifications. So by making those targets "hot", the Allies drew resources away from other targets they would pursue in the future.
The strategic bombing of German industrial centers incurred huge costs: in some missions beyond the range of fighter protection, something like 30% of bomber craft were shot down, which was seen as an unacceptable loss and led to the canceling of those missions. But having those factories become vulnerable forced the Germans to disperse their production, which led to productivity declines of around 50%. The response to the bombing caused inefficiencies that ended up doing more harm to their production than direct losses from the initial bombing had incurred. Once again, making your opponent respond in a certain way had a bigger impact than the action itself did.
These frequent raids also meant that the Germans had to put all of their air investment into fighter planes to help defend German airspace, which meant they couldn't go on the offensive in the Eastern Front or in North Africa. Anyways, this is an interesting conception: where a traditional analysis would say that one side lost due to incurring more casualties or destruction of equipment, but in the new conception the enemy's response to defend against that action results in an overall superior outcome to your side.
The prose in this book can be a bit dry at times, so I really appreciated it when something punchy lands. Hidden away on page 259 is one of my favorite sentences: "Fighting on water, a substance upon which human beings cannot walk, has always made sea warfare technologically more sophisticated than that on land." Ha!
MacArthur isn't mentioned at all early and late in the book when O'Brien is introducing the key figures in Anglo-American strategy, but he towers over the chapter on the war in the Pacific. O'Brien really slams MacArthur, who seems bad all around. He has political ambitions, and uses political threats to extract support for his military desires, threatening to torpedo Roosevelt's re-election if he doesn't get free reign (and human lives) to do as he pleases. O'Brien bluntly says that MacArthur was "not fit for command" at this time, due to his self-declared top priorities being personal vindication and honor: these are not appropriate priorities for generals in a constitutional democracy.
The big debate in this chapter is a three-way argument between the navy, army and army air force. The navy, under Ernest King, wanted a Central Pacific thrust that would take islands in basically a straight line from Hawaii to Japan. The army, under MacArthur, wanted a Southern Pacific thrust that would liberate the Dutch East Indies and the Philippines. And the army air force wanted to liberate China and start bombing Japan from the mainland. Since the US is a democracy and all of the services had large egos and political constituencies, and since the US had the luxury of lots of resources and manpower, Roosevelt never selected a single strategy and all three ended up being pursued simultaneously.
MacArthur's insistence on the Southern Pacific thrust ended up being extremely costly in American lives and didn't achieve any strategic gains. The long duration of this campaign gave Japan plenty of time to reinforce and fortify their positions, making the invasions very challenging, even with strong sea and air superiority. And it didn't gain anything: American already had access to the Japanese home islands through the Marianas and had severed access to the Philippines and other southerly imperial holdings. The death toll of Filipino civilians was much greater as a result of the fighting than it would have been under uncontested Japanese occupation, even considering how brutal the Japanese were.
This book gave me much better understanding of the context behind the rise of kamikaze pilots. At the start of World War 2, Japan had arguably the best planes and the best pilots in the world, and they were extremely effective in combat. It's rational to use these planes and pilots conventionally, so they can fly many missions and do a great deal of damage over time. By late 1944 and through 1945, though, extreme shortages of fuel meant that Japan had to cut back on flying missions, and in particular they slashed the amount of time new pilots had to train: there just wasn't enough fuel to fly as many practice flights as they wanted to. Inexperienced pilots going into combat are very unlikely to survive their first mission, so in this context kamikaze is rational, since it will at least maximize the damage they do in their one and only mission.
I like that O'Brien has a point of view. He never covers the underlying issues in the war or ideologies (other than the UK's desire to preserve the empire), but he will casually use phrasing like "fortunately" when describing a way in which the Allies gained an advantage, or "sadly" when describing where they fell short or where the Axis advanced. He is an American living in the UK, so it's natural that he would be aligned with the Anglo-American powers, and I would think that people interested enough in World War 2 to read a technical book like this already understand why the Nazis and imperialist Japan were bad. (Of course, I'm also saddened to think that a pro-Roosevelt, anti-Hitler bias may become controversial in the not-too-distant future.)
O'Brien avoids ethical discussions for most of the book before finally addressing them near the very end. This is specifically raised by the firebombing campaigns such as Dresden and Tokyo in 1945, as well as the decision to use atomic bombs, but he briefly looks at ethics as a whole. He recounts the various positions people have taken, both contemporary and modern: interestingly, even major figures within the strategic high command such as Leahy opposed both the use of atomic weapons, seeing them as a barbaric throwback to Genghis Khan-era terrorization of civilians, and invasion of the Japanese home islands, which would cause huge losses for both sides.
O'Brien seems to believe that the most ethical course is the one that ends the war most quickly. It's debatable whether dropping the atomic bomb was necessary to end the war, but if it was, the 100,000 direct casualties were certainly fewer than the indirect casualties that would have been incurred if the war had continued for many more months.
He has an interesting brief aside comparing the end of WW2 to WW1. In World War 1, once Germany realized that it had no hope for victory, it surrendered, which saved an enormous number of German lives that would otherwise have been meaninglessly lost. In World War 2, O'Brien thinks Germany lost all hope for victory after withdrawing from the Battle of the Atlantic in 1943, and by late 1944 it was overwhelmingly obvious that it had no hope of winning. Japan had lost any hope of victory once the Marianas islands had been taken, as its high military commanders all recognized. And yet Hitler and the Japanese military insisted on continuing to fight. The ultimate ethical responsibility lay on the side of the Axis for failing to accept reality and making their own soldiers and civilians pay the price for their leaders' hubris.
The book closes with a conclusion that is brief and excellent, recapping the big strategic ideas of the book and the various personalities who shaped the Anglo-American war effort. His last sentence is very clear: "Only by stopping an enemy's movement can you hope to win a war." I think that's a great summary of his rejoinder to the traditional land-centric understanding of World War 2: the Allies won the big battles because they were able to prevent the Axis from moving, thanks to depriving them of fuel, vehicles, bridges, daylight passage and so on. The Allies were able to accomplish these things thanks to effective domination of the air-sea super-battlefield, destroying equipment on the battlefield, en route to the battlefield, while being constructed and as raw materials being shipped.
This focus on movement is also a nod to the challenges the American military has faced in the asymmetric wars we've mostly fought since World War 2: we can win every traditional land battle we engage in, but we can't keep our adversaries from falling back, regrouping and attacking again, which kept us from politically winning wars like Vietnam. That's a whole huge other topic that O'Brien references in this last section but doesn't even begin to explore, and which could easily be its own book
So, yeah! This book ended up being much longer and a little drier than I expected, but I still found it fascinating and persuasive. The reams of data O'Brien presents make it more authoritative than an opinion piece, and he does a good job at finding illustrative vignettes and some colorful personalities that bring home the visceral reality of the war, beyond the abstract spreadsheet-esque focus on production. It looks like O'Brien has written a few other books on aspects of World War 2, and is regularly commenting on current topics like the Ukraine War, and I'll be interested in checking out more of his writing in the future.
