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BY 4.0 license Open Access Published by De Gruyter Open Access April 5, 2022

Pearl Harbor in Context

  • William D. O’Neil EMAIL logo
From the journal Open Military Studies


Why did Japan choose to attack the United States, and why at Pearl Harbor? The story has ancient roots, starting with the parallels and antiparallels in the geostrategic positions and long-run economic development of Britain and Japan. Japan’s recognition of its economic inferiority and strategic vulnerability in the mid-nineteenth century prompted strikingly rapid modernization. The nation quickly became highly competitive at the Western imperialist game but struggled to adapt as the rules changed after 1917, just as China fell into chaos and the Soviet Union began its rapid rise. While profiting greatly from joining the Allies in World War I, Japan was buffeted severely by the economic turmoil of the postwar era. Together with unresolved social and political tensions from rapid modernization, this led to serious unrest. This extended to the military, which had been given disproportionate political power. Army adventurers sought to continue expansionism, ultimately miring Japan in an altogether unwinnable struggle in China and provoking serious tensions with the Soviets. The rise of Nazism in Germany was seen as providential by militarists, who pushed Japan into alliance with the Axis powers. But the alliance made war inevitable with the United States determined to stop Hitler at all cost.

Keywords: Pacific War; Japan

Eight decades after Japan’s carrier-based air raid on the US fleet at Pearl Harbor in December 1941, it continues to fascinate many, not only in popular but scholarly circles. This article briefly sketches the complex context in which the Pearl Harbor attack came about, a context essential for understanding this pivotal historical event and its implications.

Citations are provided not to the sources used in writing, which would be impossibly voluminous and detailed, but to accessible sources for further exploration. The following English-language sources are suggested for deeper reading:[1] Naturally, there are great many Japanese-language sources that lie beyond the scope of this article.

1 A clash long in the making

Pearl Harbor marked the formal opening of a struggle between Japan and the English-speaking maritime states of the West for hegemony in the East-Asian/Western-Pacific region. Britain and Japan both were island states whose national history dated back to the early part of the First Millennium, CE. For many centuries, they developed in roughly comparable ways, but in about the 1400s, Britain, in company with her Western European neighbors, started to accelerate in economic progress and by the 1700s was a world leader not only in wealth but scientific knowledge. With world-ranging naval and commercial fleets, she developed a network of conquests and settler colonies that vastly expanded and enriched anglophone society.[2]

Japan underwent no comparable transformation and by the 1800s was divided into 260 or so largely autonomous “domains,” ranging in size from fewer than two dozen villages to more than 1,000, under the overall rule of a shôgun, a hereditary military dictator. In theory, the shôgun owed fealty to the emperor, a hereditary divine monarch whose line went back into the distant mists of history but who exercised no actual power. The system was an outgrowth of a long civil war centuries earlier, and each domain was ruled by its own corps of samurai warriors who, in the absence of war, acted as administrators.[3] Japan was considerably poorer than Britain or her major offshoot, the United States.[4]

Since the 1500s, European seafarers had been sailing halfway around the world and back to trade with China, later adding Japan to their itinerary. In both Asian countries, the rulers had come to feel that the value brought by the trade was outweighed by the social and political disruption it entailed and had sought to cut off most contact with the West. The shôguns had managed this largely successfully, but the China trade was too rich to be casually abandoned and the British insisted forcefully. Despite China’s huge size and population, Britain was by the 1800s much stronger in military terms and the clashes went badly for the Chinese Empire. Many of the samurai, especially in some of the larger domains, were aware of China’s struggles with the despised western barbarians and grew anxious that Japan could be next. Their fears took material form with a squadron of heavily gunned US warships that steamed boldly into Tokyo Bay in mid-1853, to present a series of demands relating to trade and maritime safety. These were modest and not too costly to Japan but a great many Japanese, starting with the emperor, passionately opposed the whole notion of dealings with foreigners, any dealings whatever. The Americans had not sailed halfway around the world to take no for an answer, however, and with the capital under the guns of their “black ships,” the Japanese were in no position to enforce their desires. Eventually, the Americans got a treaty along the lines they sought.[5]

The modesty or otherwise of the demands had little to do with the Japanese response. To a great many Japanese, any contact with the western barbarians was a defilement. They were portrayed as much like the demons of popular religion, with coarsely exaggerated features contorted in depravity and fury. There were also many Japanese who responded with warm curiosity to the westerners and eagerness to learn more from and about them and their societies, or to conduct trade with them. But fear and hostility were much more passionate and, “Expel the barbarians!” was one of the principal demands of those who thrust forward to criticize the Shogunate and insist on its reform – or abolition.[6]

In fact, the barbarians continued to pile on. The Americans sailed over the horizon and remained preoccupied with their own rebels at home until after 1865, but by 1860, the British and French, along with other Europeans, had defeated China, culminating in the capture and sack of the imperial capital, and compelled the Chinese to bow to what amounted very nearly to a colonial regime. With strong military forces in the region, it seemed natural to the British and French to go on to Japan, even though it was recognized to be not so rich a prize.[7]

Some Japanese leaders continued to be determined to expel these barbarians, insisting that Japan’s martial spirit and moral purity would overcome western weapons. But a little direct experience of barbarous cannon fire together with more information about China’s agony fortunately convinced everyone who mattered that compromise was better than unlimited bloodshed. Japan was soon yoked to her own “unequal treaties” with the westerners, but not quite so onerous as those imposed on the hapless Chinese. In the meantime, the failed drive to “expel the barbarians” had played its part in expelling the shôguns and installing a new regime. It was determined not to expel the westerners but to learn the secrets of their power and put them in Japan’s service. Many leaders spent extended periods in the West, not on junkets but in study.[8]

The period between 1860 and World War I marked the final convulsion of western overseas imperialism, with Britain in the lead but many others following. If Japan’s leaders were determined that she must gain a place among the world’s leading nations – as they most certainly were – it followed that Japan too must pursue empire just as the West did in this most imperialistic of modern eras. The most glittering prizes had already passed Japan by in its period of self-imposed isolation; by the 1890s, the pickings were meager and the competition for them fierce. Nevertheless, like their English opposite numbers, the Japanese quickly proved themselves especially eager in pursuit of imperial ventures. Instruction was obtained from France, Prussia, and Britain in modern techniques of war and warships and artillery, and other advanced military matériel was bought from Britain and Europe.[9]

2 1890s: First dispute: Hawaii

In the interim, until Japan’s armed forces were fully on a par with the best, expansion of other kinds was pursued. Hawaii was an important instance. Scarcely anyplace lay farther from other major human habitation than the Hawaiian Islands, more than 2,000 nmi from anywhere other than tiny islands with at most a handful of inhabitants. (The symbol nmi stands for nautical miles. 1 nmi = 1,852 m, or approximately 6,076 feet.) Owing to their remoteness, it was not until 1778 that westerners, English explorers, came into contact with them, finding a robust late Neolithic society. In the late 1800s, westerners, mostly from the United States, came to dominate the economy, and in 1893, they overthrew the Hawaiian monarchy and sought US annexation of the islands.[10]

A unique geologic history has given Oahu a broad central valley cut with rivers flowing into a basin spanning about 5 nmi, known as the Pearl River Delta. It was apparent to American naval officers, and others, that if the bar at the mouth of its outlet were dredged to allow large ships to pass, the delta could relatively readily be made into a harbor capable of sheltering vast fleets – Pearl Harbor, as it came to be called even before the first spade was turned. It is by far the best harbor anyplace in the middle of the Pacific, the best for thousands of miles in any direction, a strategic “pearl” beyond price.[11]

There was much resistance in the United States to acquiring territories overseas and initially even the strategic defense arguments for Hawaii were insufficient to gain Senate approval. However, sugarcane growers in Hawaii had imported large Japanese workforces and many in the Japanese government felt that the large and growing Japanese population entitled Japan to claim a dominant role in Hawaiian affairs. It was the heyday of gunboat diplomacy and Tokyo sent a naval squadron; its men ready to go ashore to insist on their point. Many in Congress who had opposed annexation found the threat of the Japanese navy persuasive. US annexation of Hawaii became law on July 7, 1898, just as the Spanish-American War was well underway.[12]

3 1895–1910: Japan becomes a major state[13]

While Hawaii was a disappointment for the Japanese, greater attractions lay closer to home. A war was provoked with China which the island nation was widely expected to lose, but instead won. Following in the European imperialist mode, victorious Japan wrung a series of trade and territorial concessions from China as the price of peace. But non-westerners were not meant to benefit from imperialism, as the Europeans saw things, and Russia, France, and Germany leagued in what was called the Triple Intervention to demand that the Japanese give up some of the most valuable of the prizes they had won. Unable to match the strength of three of the greatest of European powers, Japan complied, sullenly.[14]

Tokyo moved to consolidate control over Korea as well as Taiwan, the first two substantial prizes of Japanese imperialism. Tsarist Russia, meanwhile, had gained effective control over Manchuria (as Northeastern China then was known) following the Triple Intervention and was moving to take advantage of its resources. Japan in Korea and Russia in Manchuria were nervous and wary neighbors. Russia’s size and manpower made it a dangerous opponent for Japan, which was still in the early stages of industrialization and had quite limited financial strength. But popular pressures soon thrust Japan’s leadership into war with Russia, notwithstanding their misgivings. By striking swiftly without warning and with all their force, they reckoned, it might be possible to overcome Russia’s forces in its Far East before more could be mobilized and dispatched from Russia’s European centers. Japan’s military forces performed superbly and delivered a victory that surprised and impressed the world. Yet, the price was high and the rewards, inevitably, could not meet popular expectations, leaving a sour residue.[15]

Part of this was directed at the United States which for reasons of prestige had taken on the role of mediator. There was also rising hostility accompanying US racist reaction against growing Japanese immigration. Despite some more positive turns in relations, the overall trend was negative.[16]

Racism was everywhere a major factor in imperialism, and Japan and the United States were no exceptions. The specter of race war was raised repeatedly by advocates of expansionism in both countries. There were relatively fewer US expansionists, but the presence of substantial domestic minority populations and continuing immigration made for much domestic racism. The net effect was to make racial animosity and suspicion a corrosive constant in US–Japanese relations.[17] Awareness of America’s mounting economic power and ambitions increased Japanese concern. Nevertheless, there were also many amicable and positive notes in the relationship.[18]

4 1910–1920: The fall of one empire and the rise of another

The racist concepts of Japanese imperialists generally focused on places seen as racially compatible, notably China and Korea. The 1905 victory in the war against Russia had left Japan in undisputed control over Korea, and in 1910, Japan proclaimed that Korea had been absorbed into its empire. China in the meantime had dealt nowhere nearly as well as Japan with its contacts with the West and as a result was staggering. Finally, in 1912, China’s ancient imperial system crumbled and gave way to a chaotic “republic.”[19]

Japanese leaders were still working out how best to take advantage of developments in China in the summer of 1914 when it became clear that Europe was sliding into a continent-wide war and the question of Japan’s response became pressing. Germany’s example had weighed heavily in the formation of the modern Japanese state. Many important leaders felt strongly that Germany must surely win the war, based on its national strength and warrior spirit, and that Japan should align herself with the Germans. Nevertheless, a strong-minded foreign minister brusquely pushed a declaration of war against Germany and its Central Powers allies through the cabinet and formal imperial approval. This proved to be a masterstroke, for not only did it seat Japan on the victors’ side of the peace table in 1919 but enabled the country to sweep up Germany’s considerable possessions and concessions in China and the Western Pacific at very little cost, all while making gargantuan profits for Japanese industry through sale of war material to the Allies. Japan successfully resisted dispatching troops to fight in Europe or the Middle East, only sending a small naval contingent to aid in escorting convoys in the Mediterranean. For Japan, it was truly a “great war.”[20]

5 The turbulent twenties and thirties[21]

The Japanese as a people were intensely ambitious for their society and nation to stand among the first rank, worldwide. Economic development was high on the agenda: everyone could see that Americans, to take the leading example, were far wealthier than Japanese. Japan also needed to be strong enough, many were determined, to rebuff any western aggressions along the lines of the Triple Intervention. There were deep, passionately held divisions regarding the details of these and other objectives, and how they might best be pursued.[22]

Broadly speaking, there were two main lines of policy that gained strongest support in the two decades following World War I. One was expansionist military conquest, the other liberal internationalism, involving what we might call “amicable competition” in the world markets. Its proponents sought to model Japan on the western democracies, particularly the United States. They had studied the history and economics of the United States and the West and understood very well that great and powerful as America was in the 1920s, just a century earlier, it had been small (in population) and weak. The Japanese, they felt sure, could not only match the United States in economic growth but close the gap. And the westerners would accept Japanese trade on equal terms, they believed, because the West’s most esteemed economists argued that free trade conducted without restrictions could enrich everyone and result in the greatest economic growth for all. If Japan, through ingenuity and hard work, could produce goods of superior quality and lower cost, then it would surely be successful.[23]

The logic was good, as the Japanese “economic miracle” after World War II dramatically illustrated, but Japan’s approach was poorly considered and the circumstances were not favorable in the 1920s. World War I was followed by a severe depression, in Japan as well as virtually everywhere, leading to much unrest. Then came a wave of especially intense US racism directed at Japanese immigrants and culminating in hate-fueled legislation that severely undercut the credibility of the internationalists. US tariff laws were stacked against Japan, seemingly without any reference to actual American economic interests.[24]

Then the Great Depression caused deep disruption and damage in Japan. Exceptionally able financial management at the national level spared Japan its very worst effects, but suffering was nevertheless intense, especially in agriculture, which was still the backbone of the economy. Famine stalked the countryside and tens of thousands of families sold daughters into prostitution just to eat.[25]

All around the world, the economic and social turbulence of the 1920s and early 1930s destabilized settled institutions and patterns. In Japan, still finding its feet after the revolutionary changes of the late 1800s, the disruption was severe, made all the worse by weaknesses in the structure of government and by the unsettled legacies of the revolt against the Shogunate 70 years earlier.[26]

Once they had seen off the last shôgun and installed the teenaged Meiji Emperor as biddable figurehead of state, the men who had made the revolution faced the choice of how Japan was to be governed. For their purposes, it needed to be in the modern – which was to say Westernized – fashion. A constitutional monarchy seemed suitable, with a cabinet government backed by a parliament holding limited powers to provide a greater sense of legitimacy.[27]

Governments in more or less that mold seemed to work adequately in places such as Prussia and Austria. Yet, it was a form that had evolved in Europe and might not serve as well for Japanese who for 20 generations or more had lived under the military “tent governments” of successive shôguns. The elements of democratic control, slender though they were, seemed especially concerning.

The revolutionary leaders and re-founders of the “restored” imperial state, the so-called Meiji oligarchs, were particularly concerned about leaving the affairs of the state in the very uncertain hands of civilian politicians. As a safeguard, they gave much power to men whom they felt confident would see matters much as they did, military men. Except in budget matters, the army and navy were each made almost entirely independent of the cabinet and prime minister and given the power to bring the civilian government to a standstill. Imperial expansion was the prime mission as most military leaders saw it, particularly the army leaders.[28]

This was a view with wide public support, support which grew over time. The popularity of the armed services surged with the victorious wars against China and Russia. Scandals involving corruption in military procurement and heavy-handed intervention against popular government policies put the military on the defensive, but only temporarily.

The period following World War I brought revolutionary social and political ideas to Japan as elsewhere. The authorities were sharply hostile to socialism and communism, and took repressive measures, but more sympathetic to right-wing nationalistic theories that were markedly more popular in any event, increasingly so as time went on.[29]

In 1921, the United States called for an international conference on naval arms control to meet in Washington. All the major naval powers were building up their fleets and there were concerns that the arms race could lead to another war. The resulting Washington Naval Treaty fixed the aggregate tonnage of battleships at no more than 525,000 for each of Britain and the United States, and 60% as much or 315,000 tons for Japan. (A “standard” measure of tonnage was set for treaty purposes.) To Japan’s statesmen, including the more thoughtful of her senior naval officers, this came as a godsend, freeing her from the specter of bankruptcy in trying to keep up with the far richer Britain and America. But to an anguished group of fleet officers, it was an outrage, one more humiliation inflicted by the arrogant Westerners. Unrest over naval arms limitation spun on through the 1920s, leading extremists to assassinate or attempt to assassinate several of those involved.[30]

In 1930, a second conference convened in London to extend and refine the limitations. Despite the impassioned demands of the navalists, Japan again was forced to accept inferior ratios. An assassin fatally wounded the prime minister who was held responsible for this unbearable humiliation and several plots to overthrow the government were hatched, although all ultimately misfired. Fury raged among many younger naval officers.[31]

Like many powers with overseas empires, Japan had separate and semi-independent army formations for colonial occupation. After defeating Russia, Japan had taken over her lease of the Kwantung (Liaodong) Peninsula in northeastern China and garrisoned it with the Kwantung Army, which also guarded the Japanese-owned South Manchurian Railway. (The Japanese word used here for “army” can apply to virtually any military organization and does not imply large size, as its translation would seem to in English.)

Key officers were determined to wrest Manchuria away from China altogether, and in 1931, some staged a phony incident of sabotage on the railway as an excuse for a lightning campaign to conquer the province. This aggression, with government approval only after the fact, brought Japan international condemnation and ostracism but was buoyantly popular with the Japanese public. The Kwantung Army set up their own puppet state, called “Manchukuo,” with the intention of developing it as a source of resources and wealth for imperial expansion.[32]

By the early 1930s, the Chinese Nationalist Party, under the leadership of Chiang Kai-shek, had gained effective control over most of the country. (Chiang was his surname.) Although they still had a very long way to go, the Nationalists made some start toward creating a genuinely modern and humane China.[33] But to Japanese expansionists, China existed only to be dominated and exploited. Throughout the mid-1930s, Japanese army officers in North China, often aided by independent adventurers, nibbled away at Chinese territory and rights. Chiang, wary of the Japanese army and deeply preoccupied with other problems, compromised rather than fought.[34]

Most of the Japanese army high command, however, was more interested in Russia than in China. Eastern Siberia was rich in minerals and pasture, and poor in human population, perfect “Lebensraum” for a Japan concerned about “overpopulation.” And the Soviet Union was believed (wrongly) to be planning to invade Manchuria and Korea to reverse the verdict of the Russo-Japanese War.[35]

The government – the cabinet – had virtually no control over the actions of the military. Nor did the senior leadership of the armed services have much control over the actions of their supposed subordinates. Cabinet officers and other high officials were frequently the targets of assassins, whether military officers or simply right-wing fanatics. Senior military officers were attacked by their juniors. Assassins struck to demand action or inaction, or to punish it. Their beliefs varied but all were animated in one way or another by a sense of, “Make Japan great again,” a summons to restore the lost glories of a reimagined imperial past. As the emperor was an aspect of divinity, this was a holy calling justifying mortal violence and mortal risk. This “government by assassination” meant in effect that Japan was ungovernable, and that determined, cohesive groups could set policies in the nation’s name and force the government to accept them.[36]

In 1937, army adventurers – with a major assist from their naval colleagues and rivals – blundered into a full-scale war of conquest against China, a serious disaster in terms of the army’s real priorities, let alone the nation’s. Conquering China was an impossible project; although the Japanese army was distinctly superior and won most of the battles, there were seven Chinese for every Japanese, and they were intensely hostile to the invaders. The Japanese talk of Asian unity (under Japanese domination) found an almost entirely unreceptive audience. Yet, no one had the wit or courage to free the nation from the China quagmire.[37]

America was Japan’s largest hard-currency market, and nearly her exclusive source of the petroleum and other resources essential for military purposes, including attacking China. The American public was not at all pleased, and made its displeasure known to its representatives. But few really wanted to go as far as cutting off exports of war supplies to Japan, let alone contemplate military action on China’s behalf.[38]

6 1939–1940: The slide to Pearl Harbor[39]

The real concern for President Franklin D. Roosevelt (in office 1933–1945) and other top American foreign policy leaders was not Asia but Europe, where Adolph Hitler had gained power in Germany in 1933 and soon began ranting about and preparing for war. Americans were immediately more hostile toward Nazi Germany than Imperial Japan and more disturbed about the threat posed by Hitler.[40] Their concern grew when Germany initiated war in Europe in September 1939, fearing that it might be very difficult for America to stay out, and Hitler’s Blitzkrieg victories over Denmark, Norway, the Low Countries, and France in the spring of 1940 prompted acute alarm. Nazi propagandists suggested that the United States might be next, hoping to frighten Americans into appeasement of Germany and rejection of aid to Britain.[41]

The Japanese watched Germany’s victories with intense envy. Tactical success in China bought them little; the drain on Japan’s economy and manpower could not be sustained indefinitely. The army could not back down by simply pulling out of China: it had loudly trumpeted its ability and determination to overcome the Chinese opposition and to fail would seriously undermine its political position. Meanwhile, Japanese expansionists were highly excited by Germany’s progress of conquest. Japan, they insisted, must join with Germany to gain a share of the fruits of victory over the West, a “never-to-be-repeated” opportunity to build a vast empire spanning much of Asia and the Western Pacific. Hitler was amenable, and the “Tripartite Pact” was duly negotiated and signed in September of 1940. It did not directly commit Japan to fight Britain nor Germany to fight China, but under it an attack by an outside country on one signatory was to be counted as an attack on all. Although not so stated openly, the outside threat all parties had in mind was the United States, as American intelligence quickly confirmed. In the eyes of the Roosevelt Administration, in signing the Tripartite Pact Japan stepped from being a vile nuisance to a deadly threat that could tilt the balance in the war with Nazi Germany that seemed increasingly likely. Unless Tokyo denounced the Tripartite Pact, war with the Americans was only a matter of time.[42]

For Japanese expansionists the question was not whether to attack but whom, when, and where. Soviet Siberia was one target, climatically harsh but nevertheless rich in resources. But the Soviet army had substantial mechanized forces, essential to fight in the vast open lands of Siberia, which the Japanese could not afford to match. Nor could Japan raise enough troops to fight China and the Soviets at the same time. Japan’s naval leaders had long been attracted to the south, to Southeast Asia with its great rice crops, tin, and rubber, and even more to the islands of the Netherlands East Indies (NEI) – modern-day Indonesia – rich not only in crops and minerals but above all in petroleum, the fuel the navy desperately needed to fight a protracted war (and the army did as well). Japan had spent years stockpiling oil, bought mostly from the United States, but had accumulated only enough for less than 2 years of war, at best.[43] By the end of 1940, there was wide agreement in Tokyo on a southern strategy.[44]

In Japan’s process of decision, nothing was as it seemed. The emperor was revered as the sacred embodiment of the nation, but his authority extended only to solemnifying the decisions of the cabinet and the army and navy high commands. Pro-military firebrands had assassinated two finance ministers for lack of sufficient pliability, and no one was eager to become the third. The other top strategic policy officials, the prime minister, minister of foreign affairs, minister of war, and minister of the navy, were all either active officers of the army or navy or else selected by the military services. But this was not to say that the staffs of these departments took the wishes of the top men as final. The army and navy staffs in particular had cliques and cabals of officers, graduates of the service war colleges, who developed and pursued their own passionately held ideas about policy. They harangued, pressured, and sometimes assaulted superiors. They had narrow responsibilities but broad influence.[45]

On the whole, its graduates were not good advertisements for the merits of Japanese postgraduate military education. Few Japanese officers had the equivalent of a university degree to begin with and their war college curricula were narrowly focused. Some naval officers studied English and served in posts in America or Britain, as did a very few army officers, but they were unwelcome in the ranks of the activists, who hated and despised westerners, and particularly English speakers. Naturally their racist prejudices equipped them very badly to understand the ideas and plans of their chief opponents. Their thinking was narrowly Japan-centric, and they could not see things in a global or even multinational perspective. They had scarcely any understanding of logistics on the broad scale, nor much capacity to calculate odds at the strategic level. They were not the people who should be steering the ship of state, but there was no one to wrest the tiller away from them.[46]

There were divisions in the top commands of both services. The admirals in particular were split sharply between those who continued to believe that Japan would do best to work with the Anglo-American maritime powers – known as the “treaty faction” – and the “fleet faction” (or “command faction”) who insisted that Japan must press for dominance in the Pacific, even at the cost of war with Britain and America. By the late 1930s, the mid-level radicals in the navy were all deeply committed to the fleet faction.[47]

Many in the army thought that it should not be too difficult simply to seize the East Indies without other involvement. The Dutch colonial administration had very limited strength in the islands, and with the Netherlands occupied by its Nazi conquerors, there could be no reinforcements from home. Why could the army not do as it had in Manchuria: very swiftly take the islands and present the world with a fait accompli, impossible to reverse short of all-out war. But British forces in Singapore, right on the flank of any advance into the Indies would present a serious menace unless neutralized, and Hitler was pressing Japan to capture Singapore in order to weaken Britain. It was entirely possible to take Singapore as well, the army felt sure. Bases would be needed in southern French Indochina, but France too was under the Nazi heel, and French forces in the region were negligible.

The real question was the United States. The US army was weak in numbers and above all in spirit, as the Japanese army staff saw it, and Americans would never make good soldiers. Their navy was stronger overall, but nevertheless distinctly weaker than Japan’s in the Pacific due to the need to split its forces between the Pacific and Atlantic, and lacking in the warrior spirit that makes a truly effective fighting force. Japan had been pouring its resources into its navy for decades and surely it should be strong enough to protect against the degenerate, weak-willed Americans. In the army’s view, it should not be out of the question to take on the Americans.

A considerable proportion of the navy’s fleet faction officers were fundamentally in agreement on this. But a number of officers, mostly quite senior, who had direct contact with the US navy in earlier years and had studied it felt anxiety or even outright dread at the prospect of having to fight it. Whatever the army might suppose, the martial ardor of American sailors was clearly quite adequate to ensure effective operation of their fighting ships and their commanders were not lacking in professional competence or aggressive spirit. If Japan’s fleet became tied down in attacking the Indies, the Americans could steam out from their base at Pearl Harbor and fall upon the Japanese with serious results. Moreover, although not yet at war, the Americans were already closely supporting Britain and it was unlikely that they would sit with arms folded as Japan delivered further heavy blows to their de facto ally. Several wargames conducted in 1940 and 1941 were interpreted as giving strong indication that it was far too hazardous to count on the United States failing to intervene in any Japanese southern advance.[48]

For most of the two decades before World War II, the American public was uninterested in spending on the armed services and most members of Congress naturally went along, resulting in generally low appropriations for building new ships and even lower for new army equipment. (The army and navy’s air arms got the greater share of what appropriations there were, but their funding was still meager.) Nazi Germany’s lightning conquest of Western Europe in the spring of 1940, combined with its propaganda about leaping over the Atlantic, brought a very marked change, however. In June and July of 1940, with remarkable speed, the Two-Ocean Navy Act was passed and signed, providing for a massive expansion of the fleet, intended to ensure absolute US domination in both the Atlantic and Pacific Oceans simultaneously. It would quickly expand the US fleet in the Pacific far beyond anything Japan could possibly match. And shortly before, the president had asked for and received money for 50,000 airplanes and new facilities to produce 50,000 per year. Japan’s prospects of matching the United States at sea, slender enough at best, were soon to be altogether eclipsed.[49]

For the leadership of the Japanese navy, the only rational, responsible course would have been to insist that the whole thing was entirely out of the question, that Japan could not fight the United States with any real chance of national survival, let alone of victory. But this was completely unacceptable, not only to the army and the right wing but to the dominant elements in their own service. They were utterly determined that Japan must, as a matter of national survival, gain control of the Asia-Pacific region and its resources; the navy simply had to enable this regardless. No dissents or cautions were to be permitted, on pain of assassination. Bound by patriotic and professional duty, the top naval leaders swore to defeat the Americans or die in the attempt.[50]

The Japanese navy’s plan – or hope, to be more accurate – had long been to lure the US fleet into a great set-piece battle in the Western Pacific early in the war, before the United States could mobilize its full strength. Recognizing the risk that the Americans might not cooperate, senior leaders now decided instead to launch a bold raid on the US Pacific fleet in its Pearl Harbor base. If they could inflict a devastating defeat on them, the Americans might despair, the Japanese hoped, and decide that the potential gain from continuing to fight was not worth its cost. It was in effect a mirror of the strategy that had worked against Russia in 1905. Russia had given in after initial defeats largely because she faced a revolution at home that was far more dangerous to the survival of the régime than any losses in the Far East. The Japanese hoped that the threat of Nazi Germany would serve a similar purpose.[51]

It was intricate and clever, but to call such a structure of toothpicks and playing cards a strategy was stretching a point, and to wager the nation’s whole future on it was plain folly. It all hinged on the decisions and actions chosen by Americans, not Japanese. It assumed that the Americans would give in early, before Japan’s strength was exhausted. But while Japan had no resources to replace early losses, the United States could afford to lose its entire fleet and another would spring forth, like dragon’s teeth, by 1944. In a phrase going around among high-level war skeptics in Tokyo, Japan was playing chess without a checkmate.[52]

7 Thirty-two weeks to Armageddon[53]

Although many in the military insisted on immediate decision for war, Japan required months to prepare her forces beforehand, particularly those of the army. From the spring of 1941, long before any formal decision, Japanese forces all over East Asia were building up personnel, equipment, and supplies; conducting training exercises; and moving into strategic positions. It could not be entirely concealed, and America and the other major powers could clearly smell war in the air.[54]

While many in Tokyo were impatient for war, others still sought peace, among them the emperor. While lacking in legal power, the emperor could exert great moral authority, as long as he exercised it rarely and carefully. Moreover, his formal approval was required to go to war and while he could not withhold it in the face of the government’s advice, he could insist on asking questions. How much more he might have done was unclear and Hirohito was not the man to press the issue, but he could and did drag out the decision for war.[55]

Since Roosevelt and his government did not wish war with Japan at all and since if there was to be one, the longer it could be delayed the better from their perspective, all this led to months of half-serious nearly antipodal negotiation over possible terms for peace.[56]

The United States did not yet have a centralized intelligence agency and its intelligence resources were exigent by today’s standards, but its diplomatic and military intelligence apparatus was reasonably efficient nonetheless. American cryptologists, in particular, were among the very best, and they had recently scored a remarkable coup by breaking the complex electromechanical cypher system used to encrypt the cables sent by the Japanese diplomatic service. There was a great deal of vital information never transmitted in diplomatic cables, but the ability to read most of them nevertheless revealed much of importance that helped to illuminate Japan’s actions and intentions.[57]

None of this made it easy for top officials in Washington to form a clear idea of what was truly going on in Tokyo. But that was all but impossible even for Japanese insiders. No one in Tokyo had power of decision anything like that of the U.S. president. The issues of war and peace were hammered out at frequent liaison conferences attended by the top civilian and military leadership. The decisions reached by these conferences were formally ratified by largely ceremonial imperial conferences, with the emperor and his top advisors added to the group. While the emperor sometimes put ministers on the hotspot, he never tried to overrule the recommended decision and it is far from clear that he could have if he wished. Over the 32 weeks between April 18, 1941, and November 30, there were 56 liaison conferences and 4 imperial conferences.[58] Few of those who attended the liaison conferences were free to speak their own minds; each represented his department or service and was under intense pressure to stick to the position it had adopted internally and insist on it. For the military secretariats and staffs in particular, the internal position was strongly influenced – perhaps completely dictated – by the cliques and cabals of extremist mid-level officers who were entirely ready to harangue and even threaten seniors who were judged insufficiently compliant. After all, it was not 6 years since an enraged lieutenant colonel, sword drawn, had burst into a meeting with a senior general and stabbed and hacked him to death. And in mid-1941, an extremely right-wing cabinet minister was gravely wounded and very nearly killed because it was thought that he might be willing to make peace with the United States.[59]

For many of these extremists, the likelihood that their favored aggressive policies would lead to a desperate struggle with America and the West was a feature rather than a bug. The pride and arrogance of the Westerners was intolerable. It was essential that they be prevented from continuing to strangle Japan, and that they be humiliated and brought low in the process. Japan needed to look beyond numbers of forces and dollars to recognize that the innate superiority and martial spirit of the Japanese warrior were what really counted. If well trained and well led, the Japanese soldier or sailor could defeat ten times his number of mongrel, soft, decadent Westerners! It was time for Japan to stop humbling herself to secure favors and begin to assert herself and demand what was rightfully hers! There could be no arguing with their absolute certainty. It might have been possible to push their demands aside, but many of the leaders really shared their sentiments or views, at least in part.[60]

In any event, the liaison conference never was able to agree on any measures that might have any chance of satisfying the Americans. The most critical issue was Japan’s alliance with Hitler, embodied in the Tripartite Pact. Japan got a perfect excuse for denouncing the treaty altogether on June 22 when Hitler, without first informing his allies in Tokyo, invaded the USSR. But scarcely anyone in the leadership was willing even to seriously consider such an idea.[61]

For the Allies, the invasion was both a deadly threat and a great opportunity. If the Germans quickly conquered European Russia, as they expected, it would yield them greatly increased resources to use in fighting Britain and the United States. But if the Soviets could hold on, the war in the east would absorb huge resources and weaken Germany in the west. Thus, it was essential for the United States to do all that it could to bolster the Russian defense. There was clearly a possibility that in doing so it might be drawn into conflict with Nazi Germany, and for Japan, to insist on honoring its alliance with Germany was ominous. Japanese diplomats tried to assure Washington that the treaty did not actually bind Japan to stab America in the back, but this was not much reassurance.[62]

The other critical issue for the United States was ending Japan’s attempts to conquer China. From the American standpoint, Japan’s readiness to make peace with China was a reasonable test of readiness to keep peace with the United States, after all. And at a time when Roosevelt was trying to build support for a broad coalition against Nazi Germany, abandoning China would scarcely have inspired confidence.[63]

To Japan’s leaders, however, dominance over China was their nation’s natural right and the Chinese were being unreasonable to resist. As part of a settlement, they insisted, the United States should undertake to force the Chinese to make peace on Japan’s terms. After the Americans made it absolutely clear that this was not going to be acceptable, no matter how worded, the liaison conference considered possible promises to withdraw from China by a date certain in the future – somewhere between 1966 and 2040.[64]

For the mid-ranking officer cliques which largely drove Japan’s agenda, the efforts to find a formula for peace with America were a diversion from the liaison conference’s true business of accelerating war preparations. While there was some value in persuading the foolish Americans to continue to sell oil for the Japanese military, it should not be allowed to interfere with Japan’s thrust to seize her own supply in the Indies. It certainly was not worth making any material concessions. The weak Americans held the weak hand and the sooner they were made to realize that the better. Japan’s Nazi allies were making great strides in Europe and soon would be ready to turn back to finish off the British, leaving America isolated in the face of Germany’s full might. Not in a thousand years would Japan have such an opportunity again, and she must make all haste not to miss it.

The immediate need was to occupy the southern portion of France’s Indochina colony to provide the air bases necessary for the attack first on Britain’s bastion of Singapore and then on the oil-rich islands of the Netherlands East Indies. With France under Hitler’s heel, it was not difficult to make an agreement allowing Japanese occupation. The mid-ranking officers were not very concerned about US reaction, and the liaison conference members convinced themselves that as long as it was all done peacefully the Americans might grumble but would make no real difficulties.[65]

A decision to invade southern Indochina, formally rubberstamped by the emperor, was made at the end of June. It was supposed to be kept very secret, but the Americans learned of it almost at once through codebreaking. They saw clearly that this was a step toward invading Singapore and the Indies and sought to warn of serious consequences. But with no direct channel to the mid-rank cliques, American messages had little effect. Japan’s ambassador in Washington had been warning of the likelihood of an oil embargo but no heed was paid – the men in Tokyo were sure of their assessment of the situation. Thus, despite all the forecasts and warnings, it came as a shock when, on the day after the landings, the United States froze all Japanese financial transactions in dollars, except as approved on a case basis. This was an end to oil and all other strategic imports from America and all others who did business in dollars. Britain, the Netherlands, and other allies quickly followed the U.S. lead.[66]

For the next 4 months, while the navy completed its preparations, Japan sought for some formula that might hold off the Americans until Nazi triumphs could relieve them of the burden. But there was nothing of substance that they were willing to offer, and Japanese promises were trading at a great discount in Washington. A number of historians, particularly in Japan, condemn the Americans for being insufficiently imaginative and determined in finding ways to appease Japan, but costly appeasement that would inevitably endanger the alliance against Hitler was a price Roosevelt was unwilling to pay.[67] Ultimately, it was Japan’s choice, and the Americans could not prevent her from choosing war.

Many historians somehow imagine that the cutoff of oil was a disastrously failed deterrent. But the American leaders had been considering such a step off and on since 1931 and always realized that its effect would be to provoke rather than deter.[68] In mid-1941, with unmistakable evidence of Japan’s intention for war, oil was America’s last weapon and there could be no possible excuse for supplying the nation that had already evidenced its aggressive intent with more of what it needed to damage the United States and its allies. No one imagined that its effect would be immediate, but cutoff in advance meant that Japan’s fleets and air forces would run short that much sooner than otherwise. And the knowledge that there would be no more could not help but put a crimp in immediate operations too. Even the hottest of army hotheads could scarcely launch an attack on the Soviet Union knowing that the fuel tank was almost sure to run dry before they could reach Irkutsk.[69]

The damage that the Japanese were able to do in the first months of the war was greater than the Allied strategists had reckoned on, in large part due to disappointing performances by the major American and British top commanders in Asia and the Pacific. But in the end, it availed Japan nothing at all.[70]

Japan did have an alternative, one it had pursued with success 27 years earlier, at the start of World War I, when it had cast its lot not with the Kaiser’s Germany but with the western maritime powers. It had been the logical choice in terms of Japan’s strategic interests in 1914 and would equally have been in 1941, leading it again to reap the golden treasure of the maritime powers’ victory rather than the whirlwind of German defeat.[71] But the coolly calculating worldly statesmen of 1914 were altogether different from the narrow right-wing populist fanatics of 1941.

  1. Conflict of interest: Author states no conflict of interest.


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Received: 2021-12-03
Accepted: 2022-02-15
Published Online: 2022-04-05

© 2022 William D. O’Neil, published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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