Imperial Japan: 1894-1945
Imperial Japan: 1894-1945
EDITOR'S NOTE: This article was originally written for Japan Society's previous site for educators, "Journey Through Japan," in 2003.
Between the Meiji Restoration of 1868 and the mid-20th century, Japan created an enormous empire stretching from Alaska to Singapore, controlling as much territory and as many people as any of the great powers of Europe. Why did Japan’s leaders choose to develop an industrial economy and a powerful military machine in the late 19th century? How could they succeed, given that no one could have predicted such achievement from a non-Euro-American island nation at the edge of East Asia? Why did they decide to overpower their neighbors and gradually to take their territory, beginning with the island of Taiwan, then Korea, then part of mainland China, the Philippines, most of the Pacific Islands, and more? What led Japan into its ill-fated war with the United States?
Answering questions like these requires not only “facts” such as industrial production statistics or treaty texts or numbers of aircraft carriers, but also an understanding of Japanese views of their position in Asia, and of Japanese culture itself. As non-Japanese readers, we must humanize the Japanese, even in a period when they were becoming our avowed enemies, and see people from this most “other” of places as unique individuals rather than as a racially defined, homogeneous enemy. This approach will produce a very different narrative of modern Japan from that of motion pictures, comic books, government propaganda, and textbook summaries. Their stories, with clear good guys (us) and bad guys (them), with black-and-white portrayals of Japan as an agent of evil, cannot stand up to historical inquiry if we consider Japanese to be human beings. Our purpose lies not in justifying the behavior of any historical actor—Japanese or American—but in learning how people in the past made choices and decisions, understood their worlds, and created the cultures and events of human history. This essay will present a basic timeline of Japanese imperial history as a first step in that process.
Japan’s Early Motivation for Empire
After 1868, the new leaders of Meiji Japan worked hard to improve their country’s status in the world and to abolish the unequal treaties and racial discrimination imposed on them by the European powers and the United States. They watched nervously as Southeast Asia came under French rule, Russia moved rapidly into Manchuria (northeast China), the United States pushed westward from California to Hawai’i, and Britain fought two wars to advance its interests in China. What strategies could Japan use to preserve its independence? What models of international behavior should it follow?
Historians have advanced many reasons why Japan took the great northern island of Hokkaido and the Ryukyu Islands (including Okinawa) as part of its territory, industrialized its economy, built up its military, and expanded its interests and its territory outside its “home islands.” Certainly the need for national security haunted the leaders of Meiji Japan. They had begun their program of Euro-American industrialization largely in order to defend against the foreigners—to jõi, “expel the barbarians.” Looking outward from their islands they saw Korea and China overwhelmed by enemies, unwilling or unable to defend themselves and offering to Britain and Russia the opportunity to set their sights on Japan. They worried especially about Korea, which (in strategic terms) they saw as a ‘dagger pointing at the heart of Japan.” (A look at the map will confirm this!) In the very first years of the Meiji period, many of Japan’s new leaders advocated a quick invasion of Korea for two reasons—to combat a Russian, Chinese, or European takeover, and to give their own impatient samurai warriors a noble mission. But calmer heads won the debate, and the invasion was postponed until Japan was more independent in modern weaponry and well trained in military strategy. The war party had to be content with forcing the Choson king to sign an unequal treaty giving Japan the kinds of privileges in Korea that Euro-Americans had in Japan.
By 1894, the army and navy had met that goal by purchasing and manufacturing high-quality European-style weapons and by reorganizing the military along European lines. Meanwhile, the Qing government in China and the Choson government in Korea had weakened further still. Claiming to be aiding a pro-Japanese group in the Choson court, Japan sent troops to attack both Korea’s national army and the Qing troops that came to their aid. Japan’s victory was rapid and total, on land and sea, demonstrating the effectiveness of Euro-American technology in East Asian hands. Through a peace treaty, Japan took as colonies the island of Taiwan and the Liaodong peninsula, both parts of the Qing empire, as well as a huge sum of money. Japan also ended Qing power in Korea. By looking at a map, however, we can see that Japan’s victory directly threatened one of the expanding European empires, Czarist Russia. With help from Germany and France, Russia pressured Japan to return Liaodong to China in exchange for more cash. Much of the Japanese public, delighted by Japan’s easy victory, rioted against the government for caving in to the foreigners’ demands.
Japan had its chance for revenge a decade later. After careful planning, an alliance with England (1902), and a very costly military build-up, Japan went to war with Russia in 1904, effectively eliminating the Russian fleet in southern Liaodong in the initial battle. Land campaigns in northeast China resulted in gradual success, but with thousands of lives lost. The navy then provided the crucial difference. Under Admiral Togo, Japanese ships intercepted and destroyed the Russian Baltic Fleet, which had steamed all the way around Africa to reach the Pacific. Both sides, tired of the war, sought the assistance of United States President Theodore Roosevelt, who helped them work out a treaty. Japan obtained control over Korea and southern Manchuria and possession of the southern half of Sakhalin Island but received no cash payments, despite Japanese victories. Again, the Japanese public felt that Japan had not received its due, and rioting broke out in the major cities.
Some scholars believe that the leaders of Japan intended from the beginning to establish an empire outside the home islands, while others contend that Japan’s overseas expansion was unplanned. However it may have originated, the idea of Japan as the powerful center of a revived Asia found fertile soil among the Japanese people. As the nation won these initial wars, Japan’s business and strategic interests in Korea, China, and Southeast Asia expanded, and so did their security perimeter. Korea was the first area of concern, followed by Taiwan, Manchuria, Shandong, the entire China coast, and finally the Philippines (recently colonized by the USA) and the Dutch East Indies. Anxious about supplies of raw materials necessary for industrial and military development, especially coal, iron, rubber, and oil; afraid of European involvement, especially Anglo-American naval strength; and inspired by military success, Japanese corporations and the Japanese military moved rapidly to secure zones of influence all over East Asia. Colonists went abroad in large numbers, taking their wealth and labor with them and establishing communities which demanded and received protection from the Japanese government. More and more Japanese troops went overseas to secure the safety of civilians and industrial installations.
Mobilizing the Nation for Empire Building
The engagement of government, private business, schools, and ordinary citizens in Japan’s overseas empire, as well as the riots which occurred when Japan’s honor was not respected, reveal a deep patriotism and nationalism among ordinary Japanese, a feeling very important to the Meiji government. Using a variety of tools—public education, well-controlled media, veterans’ associations, local religious institutions, among others—the government planted in many (some say most) Japanese a deep emotional tie to the Emperor (Tennõ), the government, and the idea of Japan itself, which was called the kokutai, the uniquely Japanese nation. This provided an effective motivation for people to sacrifice, to be patriotic, and to lay down their lives or their work for their country. Though not entirely different from nationalism in other countries, this public-spirited emotion sank deep roots in Japan in part because of the timing of its genesis—it came when Japan could easily be perceived to be in dire straits, its very existence at risk.
Many people did manage to resist the government’s well-planned campaign for national loyalty, but it convinced the majority that their country was superior to others, the “land of the gods,” a notion which could be found in some very old texts. Westerners could be admired for their technology and knowledge, but many Japanese believed that only they possessed the special warrior spirit of an unconquered people, with its single and uninterrupted family line of rulers descended from Amaterasu, the goddess of the sun (Tennõ means “heavenly sovereign”). Some Japanese, however, noticed that powerful people in Japan became wealthy through corruption or political influence, and that workers and farmers received only a tiny wage for their patriotic, backbreaking labor. Convinced that this inequality had to be corrected before Japan could be a great nation, they tried to make their voices heard. But without a free press or academic freedom, and in the face of consistent government repression, they could not reach most of the people. The Meiji state and its successors feared domestic dissidents to the point that even groups of a dozen socialists or fewer could be subjected to police raids, confiscations, and prison terms.
When the Meiji Emperor died in 1912, many Japanese felt a terrible sense of loss, for the figure of the Tenno, however little real power he may have had, represented Japan’s new international success and stature to them. Ordinary people lined up outside the Imperial Palace in Tokyo to pay their respects. General Nogi, a hero of the war against Russia, committed suicide with his wife, “following their lord” in death, an act widely admired by the public. Famous writers found themselves drawn back into Japanese traditions after decades of fascination with the United States and Europe. Japanese literature after 1912 reflects a deepening sense of the value of an idealized vision of Japan’s past and the nation’s importance in the writers’ sense of who they were as individuals. Using this nationalism to their advantage, Japan’s leaders usually could rely on their people’s loyalty to the government, though they constantly worried about subversion. (A small group of leftists was arrested, and their leaders executed, for plotting to kill the Emperor in 1910.) These leaders continued Japan’s quest for wealth and power under the Taishõ Emperor (reigned 1912-1926), a weak and unstable character. Inspired by European parliamentary systems, some Japanese politicians formed parties to participate in elections to the national assembly (called the Diet); while others opposed the government because they thought it was corrupt.
World War I, the “war to end all wars” in Europe, gave Japan a new opportunity to gain wealth. With all the European powers needing military supplies and consumer goods, the Japanese moved rapidly into the world’s markets for weapons and light industrial products, providing both goods and shipping. Japanese exports almost tripled in only four years. Taking advantage of Europe’s internal conflicts, Japan moved into an East Asian power vacuum and demanded that the Chinese government, weak and decentralized after the collapse of the Qing Empire in 1912, turn over much of its economic and political power to Japan. Yuan Shikai, the military leader who had taken charge of the embryonic Republic of China, had no choice but to submit to Japan’s superior strength. At the same time, however, Japan’s arrogance and aggression caused many Chinese to join nationalist movements of their own. In colonized Korea, too, resistance to Japanese occupation took many forms, so Japanese forces fought back by killing and jailing many civilians.
These overseas conflicts coincided with growing social movements in Japan itself. Many sectors of society—workers, farmers, intellectuals, suffragists, and others—disagreed with the government’s call for obedience and national unity. Young people in the cities (called “modern boys” and “modern girls”) saw American movies, wore the latest fashions, and bought products advertised in fashionable magazines. Inspired by Russian socialism and anarchism, and by the success of the 1917 Revolution, radical Japanese intellectuals and workers tried to form unions for factory employees, to obtain better wages or working conditions or to influence the government. Some women became authors, leaders of social groups, even politicians, despite great social pressure to conform to the ideal role of “good wife and wise mother.” Intellectuals and professors taught a wide range of topics, including Marxism, Darwin’s theory of evolution, Woodrow Wilson’s internationalism, and even Freudian psychology. All these developments gave rise both to cultural excitement and to political unease, as disunity threatened the seemingly fragile post-Meiji state and society. As social and cultural diversity spread in Japan, great corporations such as Mitsui, Mitsubishi, and Sumitomo organized industry for their own profit and for production of weapons for the military. Businesses made sure they could benefit from government contracts by bribing politicians, and citizens on both the left and the right came to mistrust both the industrialists and the political parties. To whom could they turn for security and a stable reference in a confusing world?
All societies going through rapid change face problems. The world seems very unstable, and people may not know what to believe or who is right? Who should they trust when “old-fashioned values” no longer seem to be effective? Faced with all of this apparent chaos, many Japanese worried that the special “Japanese spirit” in which they had been taught to believe would disappear under the influence of Euro-American ideas and fashions. Many Japanese believed that the most important value in Japan should be unity and willingness to sacrifice for their country in order to face foreign enemies such as Britain, the United States, and especially the new Soviet Union. It is no surprise that they turned to the Tennõ as their nation’s symbolic leader and to the military as their ideal of discipline and self-sacrifice. In this view, electoral politics were inherently corrupt, for civilian leaders acted only for selfish interests, but the Emperor and the military could be trusted. However, the new Shõwa Emperor, known to foreigners by his personal name of Hirohito, was enthroned in 1926 but inherited little real power, and the leaders of Japan’s military, despite their reputation, did not necessarily have the people’s best interests in mind.
Domestic Political and Social Trends: Dissent and Response
By the 1920s, the Meiji politicians had mostly passed away, and their political heirs tried to create widespread, single-minded devotion to the country in a climate of political party division and factional rivalry. Originally based on a late 19th century German ideal of direct service to the ruler, Japan’s government now resembled a British style of rule by one of two centralized parties. Run by a tiny elite of pro-business, mostly pro-Western politicians, these parties used both policy and corruption to promote their own leadership. They did liberalize some aspects of society, allowing labor unions, giving all Japanese males the right to vote, and joining the League of Nations to participate in the international community. As a “great power”—the only one not ruled by Euro-Americans—Japan participated in naval limitation conferences, maintained its colonies by a combination of administrative bureaucracy and military-police violence in the same way Britain, France, and the United States did, and forced China to expand Japan’s treaty rights. Despite continued discrimination against the Japanese by Europeans and Americans—who continued to affirm that Japanese were not “white” people, despite their successes—Japan became a member of the “imperial club.” But Japanese internationalism, personified in Shidehara Kijurõ, Foreign Minister in the early 1920s, also posed a challenge to Japanese nationalists, who saw the politics of international diplomacy, parliamentary democracy, and compromise as weakness, in contrast to the military’s desire for further conquest.
Under the surface, economic inequality threatened the unity of the Japanese people even more in the 1920s than it had sixty years before, for industrialization had created the same tensions between workers and employers as it had in Euro-American societies. Conflicts over wages and working conditions led to unions and strikes, actions which seemed like treason to people committed to the almost religious unity of the kokutai. To combat this potential disorder, the Japanese government as early as 1900 had passed strict laws to punish anyone who promoted social conflict. Even in the relatively liberal 1920s, those laws were strengthened to give the government greater power over the press, virtually eliminating the public’s rights of free speech and assembly, rights which had never been strongly proclaimed in Japan’s constitution or law codes.
Japanese companies, especially the very large ones, learned from the government and took measures to prevent expression of worker discontent. Skilled laborers were hired for life and encouraged to link their own destinies with that of their company. Local company-based unions negotiated limited benefits for their members, while both law and custom prevented the formation of many effective national unions. Government regulation did not hamper the growth of huge manufacturing monopolies. Rather the Japanese state encouraged a dual economy of a few giant companies supplied by thousands of small operations, employing only a few people each. In periods of economic growth, these strategies proved quite effective. But tougher methods were necessary in bad times, which arrived with the crash and depression in 1929.
The Japanese economy was badly damaged by the great stock market crash because so much of its wealth came from foreign trade, which declined drastically after 1929. As the American and European economies staggered, their cash supplies low and millions of their people unemployed, they could no longer afford to buy foreign goods. During this period, the Japanese lost 50% of their overseas sales, domestic prices crashed, and Japanese incomes fell 30% on average. Ordinarily, such difficulties might produce public support for antigovernment groups like communists and socialists, whose demands included support for the poor and unemployed. But Japan’s government had discouraged even the mildest dissent, so many citizens turned instead to right-wing organizations, both civilian and military, to express their dissatisfaction with politics as practiced by the ruling parties.
These right-wing, ultranationalist groups claimed a special purity for their own ideas—the centrality of the Tennõ and opposition to international diplomacy which, they claimed, kept Japan weak by limiting its military options. They encouraged citizens to support and love the army and navy abroad, and they praised the virtues of self-sacrifice and nationalism. They also used Shintõ, part of Japan’s religious tradition, to idealize the Japanese spirit and its samurai virtues. Through local shrines and priests, who preached Japan’s superiority over other peoples and practiced rituals of “uniquely Japanese” purity and love for nature, many Japanese people became convinced of Japan’s sacred task to drive the Euro-Americans out of Asia. They also believed that making war was a central part of that mission. The beauty of nature, especially of cherry blossoms falling (constant reminders of the brevity of human life), of sacred mountains, and of the sea, came to be equated with heroic death in the national cause.
Young men, both military officers and their colleagues in civilian organizations such as the Kokuryukai (Amur River Society), expressed their nationalist passions through assassinations of politicians, industrialists, intellectuals, and others who did not conform to their rigid standards of “pure Japanese” behavior and beliefs. Prime Minister Hamaguchi was murdered at Tokyo Station in 1930, and Prime Minister Inukai was killed in 1932. Both assassinations were perpetrated by ultranationalists impatient with the corruption of party politics and eager for Japan to be driven by their own heroic values, which were expressed most obviously in the military and the drive to dominate Japan’s neighbors, especially China.
The Military Mobilizes
The military, meanwhile, had conflicts and troubles of its own. The army and navy fought one another over budgets, weapons systems, political influence in Tokyo, and Japan’s international policies. The navy, more concerned with technology than the army, had been limited in construction of large warships by the Washington (1922) and London (1930) Naval Treaties. Still, it had managed to build a strong fleet including aircraft carriers and submarines, a navy larger than any foreign fleet they might face in the western Pacific. The U.S. naval presence in Hawai’i made the United States the main target of naval war planning, and their main anxiety lay in securing the supplies of oil needed to run the ships of both the navy and the merchant marine, since most oceangoing vessels had converted from coal to diesel fuel. Japan imported most of its oil from the USA and American-controlled oil fields in Mexico, so the Japanese military found itself dependent on its most likely enemy for a crucial material resource. The nearest developed oil field to Japan lay in the Dutch East Indies (now Indonesia and especially Brunei), at the end of a long north-south sea lane that the Japanese navy had to secure.
The army, on the other hand, found itself bogged down occupying Taiwan, Korea (taken as a colony in 1910), and especially Manchuria, where the army protected Japanese mines, factories, railroads, and large communities of settlers. Eager to demonstrate their power, unwilling to wait for diplomacy, and convinced that their allies in Tokyo would back them, Japanese army officers planned an incident which would force the Japanese government to seize Manchuria. Despite advance warning of the plot, the High command in Tokyo was unwilling to take action against its own men until it was too late. On September 18, 1931, a bomb blast on a Japanese railroad triggered a well-prepared attack in which all of northeast China was seized. By spring, large parts of Mongolia also lay in Japanese hands, and for the next six years, by treaty and by aggressive action on the ground, Japan took over piece after piece of northern China.
In the face of this direct disobedience to orders, Tokyo did nothing, accepting this huge new territory as part of the empire. They declared Manchuria to be an independent state, Manshukoku in Japanese (usually called Manchukuo in English), under a Chinese emperor. But the real governor of Manchukuo was always the commander-in-chief of the Japanese army stationed there in overwhelming numbers. The international community reacted angrily to the “Manchurian Incident,” and, after lengthy investigation, the League of Nations condemned Japanese aggression. The Japanese delegation walked out, never to return. US influence in this matter was very limited, for the United States had never joined the League in the first place, but American public opinion ran strongly in China’s favor and against Japan.
From 1932 to 1936, domestic political conflict escalated in Japan, as war in China required more and more troops and money to control the rising armed power of Chinese nationalism. The civilian government had to bow to the demands of the military, for no government could be formed or sustained without military participation. Admiration of the military, and faith in its spirit, led many Japanese to ultranationalism, the belief that Japan was inherently superior, that the Japanese military could never be defeated, and that Japanese culture and morality were uniquely pure and true.
But some Japanese people did not fall into the ultranationalist camp. Resistance came from civilian politicians fearful for their own power, intellectuals unwilling to accept the simple-minded ideals of kokutai and military virtue, from socialists, Christians, and others committed to self-determination of peoples (including Chinese and Koreans) and to the unity of human kind. The voters continued to choose the conservative and moderate political parties in parliamentary elections. In a February 1936 election, one of the mainstream parties won a majority with slogans such as, “What shall it be, parliamentary government or fascism?” Even the small socialist party made modest gains at the polls during the 1930s, in the face of a high tide of ultranationalist propaganda.
But only a week after those elections, on February 26, 1936, the Army First Division, stationed in downtown Tokyo, attacked the heart of the civilian government. After killing a number of high officials, they held several blocks of the central city for three days. Though still supporting their junior officers, the High Command finally called in reinforcements—many of them, not surprisingly, from the navy—and forced the rebels to surrender. The leaders and a few key civilian allies (including the right-wing intellectual Kita Ikki) were executed and generals who had been involved in the plot were fired, but the army remained deeply involved in politics, and the incident may even have strengthened the military’s hand—high officers could throw up their hands and say, “We’d love to help, but we’re afraid the young hotheads might rebel again!”
Though civilian ultranationalists lost a measure of influence after the “Young Officers’ Coup” failed, politicians eager to demonstrate their patriotism put intense pressure on all dissidents, including not only communists and socialists but also liberal intellectuals. Party politics revived briefly in the late 1930s, but the military and the professional bureaucrats in Tokyo combined to make the Diet’s job impossible. The chaotic operations of representative government, with their public contesting of elections and open debates over policy disagreements, reinforced the view that politics consisted only of mean-spirited self-interest, not of high-minded patriotism and loyalty to the Tennõ.
The Drums of War Sound Louder
In China, events conspired against moderate forces in Japan. In December 1936, President of the Republic and Generalissimo Chiang Kai-shek was kidnapped by two of his own generals and forced into an all-China alliance against Japan. This United Front, including Chiang Kai-shek’s deadly rivals, the Chinese Communist Party, posed a direct threat to Japanese military power in China, and the Japanese army could not allow it to gain national strength. Their mainland strategy required them to protect Japanese economic interests and defend against the Soviet Union, so the army chose full-scale war rather than endless local conflicts against armed Chinese nationalism. Only July 7, 1937, a local clash between Chinese and Japanese troops near Beijing gave them their chance. Unprepared for war—the army had just drawn up a five-year plan to produce sufficient supplies of arms and material—Japan’s generals decided to attack China before it could become a strong, unified nation. Many Japanese hoped that the war would establish a new order in East Asia, one based on all peoples’ common identity and common opposition to European and American imperialism and colonialism.
From the outset, the war did not go well for the Japanese military. Persuaded by their officers that the cowardly Chinese would not fight, Japanese troops stormed ashore at Shanghai and met stiff, protracted resistance from Chiang Kai-shek’s crack divisions. Finally victorious after weeks of battle, the Japanese army had lost tens of thousands of men and gained desire for revenge and an appetite for killing Chinese people, an emotion fed both by their losses and by the racialist propaganda of their leaders. The next city to be assaulted, Chiang Kai-shek’s capital of Nanjing, suffered the consequence. After driving out the Chinese troops, the Japanese army undertook a horrific massacre of the civilian population, with victims numbering from 80,000 to 300,000, depending on whose statistics one believes. This crime, and smaller-scale atrocities elsewhere, aided both Chiang Kai-shek’s government and its Communist rivals in stimulating ordinary Chinese to join in resistance to Japanese conquest. A Japanese-sponsored “government of China” was set up, but everyone knew it was Tokyo’s puppet. Many patriotic Chinese followed their political leaders westward—Chiang Kai-shek’s Nationalist Party and Mao Zedong’s Communist Party both set up governments in remote areas and tried to fight the invaders.
Having signed an anti-Soviet alliance with Hitler’s Germany in 1936, Japanese diplomats saw their best advantage in squeezing the Soviet Union, still the main enemy in many policy planners’ eyes, between their powerful military forces. The Axis Alliance of Germany, Italy, and Japan had been designed to prevent British, American, or Soviet meddling in East and Southeast Asia, which Japan claimed as its sphere of influence. The army tried to take the measure of the Soviet Red Army in a border clash in northern Manchuria in 1939 and took a terrible beating. Never had the Japanese faced an enemy who possessed modern armor and artillery, nor an opponent as skillful as General Zhukov. After this defeat, even the army conceded that Japan’s interests lay more in the south, and a mutual non-aggression pact was signed with the Soviet Union (one that lasted until August 1945). The rich oil fields and rubber plantations of the Dutch East Indies and French Indo-China constituted tempting targets, and the navy tried to consolidate the strategic sea routes from the home islands to all of these crucial resource bases. By the summer of 1941, with the Soviet Union hard-pressed by German invasion and Britain utterly incapable of overseas intervention, only one enemy remained to prevent Japan from ruling the entire western Pacific—the United States.
Why did Japan abandon its diplomatic relationship with the United States, which had worked fairly well, to initiate a new phase in the Pacific War, one which many Japanese knew could be disastrous? As early as 1915, American policy makers had noted the possible Japanese threat to American interests in China, and in the late 1930s President Roosevelt began to flex American muscle, especially economic power, to force Japan off the Chinese mainland. The USA (under Theodore Roosevelt) had covertly traded Japanese control over Korea for American control in the Philippines, but China was far too important a political, military, and sentimental ally for the USA to allow Japan a free hand there. After 1939, President Roosevelt refused to allow Japan to purchase American scrap metal. In early 1941, FDR threatened to cut off exports of oil. Without US oil, Japan could not operate its fleet or move its armored vehicles, could not fuel the huge merchant marine, which moved raw materials and goods throughout the Japanese empire, from northern Korea to the south seas. The only alternative supply lay in the Dutch East Indies. If Japan attacked the Dutch, the USA would certainly respond by declaring war, but how else could Japan ensure its supply of this vital resource? Japanese planners found themselves in an impossible bind. Economic interests as well as nationalism prevented Japan from withdrawing from China, as Roosevelt demanded, for they had invested blood, treasure, and national prestige in their mainland empire. But if the Japanese continued in China, Roosevelt would turn off the oil tap, and Japan could not obtain sufficient fuel without risking war with the USA.
At this point, naval planners in Tokyo ordered their finest strategist, Admiral Yamamoto Isoroku, to draw up a plan for destroying US power in the Pacific and rendering the western Pacific sea lanes, including those to the oil fields, safe for Japanese shipping. Yamamoto tried to persuade his superiors that attacking the USA would be catastrophic for Japan and that Japan would never be able to match US industrial might—he argued from first-hand experience, for he had studied and worked in the USA in the 1920s and was familiar with American military and industrial technology. But they disagreed with him, and as a good soldier and a patriot, he went ahead with his job.
The USA had military forces, mostly army, in the Philippines, but its Pacific Fleet was based at Pearl Harbor, on the island of Oahu. Yamamoto made a careful study of the harbor and its defenses and decided that it could be destroyed from the air, if the attack could be a complete surprise. Japan had the right weapons—Japanese aircraft carriers, torpedo planes, torpedoes, and fighter-bombers were the most advanced in the world at that time. After a year of diplomatic wrestling with the USA over their entirely incompatible demands—Roosevelt urging the Japanese to get out of China and the Japanese asserting their right to colonize in East Asia—Japan’s leaders, headed by Prime Minister and Army General Tõjõ Hideki, decided that they had no choice. They could not survive a continued embargo of oil, so they had to attack southward and take the rich Brunei oilfields from the Dutch. But first, they had to eliminate the US threat. So on December 7, 1941, Japanese carrier-based aircraft attacked Pearl Harbor and destroyed much of the US fleet anchored there. Unfortunately for the Japanese navy, and for Japan, the American aircraft carriers that should have been in harbor were on maneuvers at sea that day and escaped damage.
We cannot answer the question, “Why did they do it?” with any single answer. Certainly the need to ensure supplies of oil and other raw materials played a large part in the decision to go to war with the USA despite the continuing conflict in China and an industrial complex considerably smaller than that of their chosen enemy. Other factors also played their parts—a pan-Asianist ideology that claimed all of East and Southeast Asia to be Japan’s natural sphere of influence; an (ironic) anticolonialism that took “white” domination of Asians as its target; long-term Japanese antipathy for what they perceived to be American arrogance in foreign policy; and, perhaps most telling, many decades of humiliation by American racism, best symbolized by a 1924 Act of Congress which specifically excluded all Japanese from immigration to the USA, the only people singled out in this way. Whatever complex motivations led the Japanese into these multiple wars—in China, in southeast Asia, in the Pacific—they never achieved the military and industrial superiority which they required in order to win, and the years after 1937 saw Japan spiral downward into a Dark Valley of war, privation, and suffering which was to last for over eight years.