Why Japan Went to War?

* Prior to the outbreak of World War II, China was heavily supported by Germany (until 1938) and the Soviet Union. The latter readily provided aircraft, military supplies, and advisors seeing China as a buffer against Japan. The United States, Britain, and France limited their support to war contracts prior to the beginning of the larger conflict. Public opinion, while initially on the side of the Japanese, began to shift following reports of atrocities like the Rape of Nanking. It was further swayed by incidents such as the Japanese sinking of the gunboat USS Panay on December 12, 1937, and increasing fears about Japan’s policy of expansionism.

US support increased in mid-1941, with the clandestine formation of the 1st American Volunteer Group, better known as the “Flying Tigers.” Equipped with US aircraft and American pilots the 1st AVG, under Colonel Claire Chennault, effectively defended the skies over China and Southeast Asia from late-1941 to mid-1942, downing 300 Japanese aircraft with a loss of only 12 of their own. In addition to military support, the US, Britain, and the Netherlands East Indies initiated oil and steel embargos against Japan in August 1941.

Moving Towards War with the US
The American oil embargo caused a crisis in Japan. Reliant on the US for 80% of its oil, the Japanese were forced to decide between withdrawing from China, negotiating an end to the conflict, or going to war to obtain the needed resources elsewhere. In an attempt to resolve the situation, Konoe asked US President Franklin Roosevelt for a summit meeting to discuss the issues. Roosevelt replied that Japan needed to leave China before such a meeting could be held. While Konoe was seeking a diplomatic solution, the military was looking south to the Netherlands East Indies and their rich sources of oil and rubber. Believing that an attack in this region would cause the US to declare war, they began planning for such an eventuality.

On October 16, 1941, after unsuccessfully arguing for more time to negotiate, Konoe resigned as prime minister and was replaced by the pro-military General Hideki Tojo. While Konoe had been working for peace, the Imperial Japanese Navy (IJN) had developed its war plans. These called for a preemptive strike against the US Pacific Fleet at Pearl Harbor, HI, as well as simultaneous strikes against the Philippines, Netherlands East Indies, and the British colonies in the region. The goal of this plan was to eliminate the American threat, allowing Japanese forces to secure the Dutch and British colonies. The IJN’s chief of staff, Admiral Osami Nagano, presented the attack plan to Emperor Hirohito on November 3. Two days later the emperor approved it, ordering the attack to occur in early December if no diplomatic breakthroughs were achieved.

http://militaryhistory.about.com/od/worl…
Source(s):
http://www.pearlharbor.org/history-of-pe…
http://www.theamericancause.org/patwhydi…
http://en.wikipedia.org/wiki/Attack_on_P…

Japan, largely devoid of natural resources to feed its industries, looked overseas for supplies of strategic materials such as ores and petroleum. Before 1939 the United States was Japan’s major supplier. But President Roosevelt and Secretary of State Cordell Hull shut off American supplies in an effort to force the Japanese to end hostilities against China. The Japanese had long coveted the resource-rich British and Dutch colonies of Southeast Asia, and as the U.S. trade embargo tightened, the Japanese increasingly looked southward for raw materials and strategic resources.

Only the United States stood in Japan’s path. The U.S. Pacific Fleet at Pearl Harbor was the only force capable of challenging Japan’s navy, and American bases in the Philippines could threaten lines of communications between the Japanese home islands and the East Indies. Every oil tanker heading for Japan would have to pass by American-held Luzon. From these needs and constraints, Japan’s war plans emerged.

First, its navy would neutralize the American fleet with a surprise attack on Pearl Harbor. Japan would also seize America’s central Pacific bases at Guam and Wake islands and invade the Philippines. With American naval power crippled, Japan’s military would be free to seize Burma, Malaya, Singapore, and the Dutch East Indies in a series of rapid amphibious operations. Japan would then establish a defensive ring around its newly conquered empire by fortifying islands in the south and the central Pacific.

Japan’s leaders were convinced that Americans, once involved in the European war, would be willing to negotiate peace in the Pacific.

To block Japanese ambitions, the United States Army had scant resources. Two small forces constituted the heart of the American land defenses in the Pacific — the garrison in the Territory of Hawaii and General Douglas MacArthur’s command in the Commonwealth of the Philippines. Both were peacetime organizations, whose days were given to rounds of ceremonies, inspections, and languid training. Officers and their wives occupied evenings and weekends with rounds of social activities and golf, while the soldiers enjoyed more earthy pleasures in the bars and brothels of Honolulu or Manila.

Yet these forces would face overwhelming odds in the event of war. The thousands of islands that comprised the Philippines lay 8,000 miles from the American west coast, but only 200 miles from Japanese-held Formosa. To defend them, General MacArthur had the equivalent of two divisions of regular troops — 16,000 U.S. regulars and 12,000 Philippine Scouts. He could call on additional thousands of Philippine militia, but they were untrained and ill equipped. Lt. Gen. Walter C. Short’s Hawaiian command held 43,000 Army troops, including two infantry divisions, coast artillery, air corps, and support troops. Thus, in ground forces, the United States had the equivalent of three divisions in the Pacific to stand in the path of the Imperial Japanese Army.

American strategists had developed two plans to counter possible Japanese aggression — one for the Navy and another for the Army. The Navy planned to fight across the central Pacific for a climactic and decisive battle with the Japanese fleet. The Army saw no way to save the Philippines and favored a strategic defense along an Alaska-Hawaii-Panama line. Writing off the Philippines, however, was politically impossible, and as war drew closer frantic efforts were made to strengthen the commonwealth’s defenses. Both MacArthur and Army Chief of Staff General George C. Marshall overestimated the chances of their own forces and underestimated the strength and ability of the Japanese. In particular, they grossly exaggerated the power of a new weapon, the B-17 “Flying Fortress” bomber, a few of which were rushed to the Philippines in the last days of peace.

All of the efforts proved to be too little, too late. The Japanese war plan worked to perfection. On December 7, 1941, Japan paralyzed the Pacific Fleet in its attack on Pearl Harbor. In the Philippines, Japanese fliers destroyed most of MacArthur’s air force on the ground. Freed of effective opposition, Japanese forces took Burma, Malaya, Singapore, and the Dutch East Indies in rapid succession. By March 1942 the Japanese had conquered an empire. Only MacArthur’s beleaguered American-Filipino army still held out on the main Philippine island of Luzon.

A Japanese army had landed in northern Luzon on December 22, 1941 and began to push southward toward Manila. At first, MacArthur was inclined to meet the Japanese on the beaches. But he had no air force, and the U.S. Navy’s tiny Asiatic fleet was in no position to challenge Japan at sea. The U.S. regulars and Philippine Scouts were excellent troops but were outnumbered and without air support. Giving up his initial strategy of defeating the enemy on the beaches, MacArthur decided to withdraw to the Bataan Peninsula. There he could pursue a strategy of defens Japan’s aggression started in 1932, with her occupation of Manchuria; later, in 1937, she started a war with China proper. As the ’40s began, her effort in China was bogging down, she was facing a U.S.-led embargo of resources (e.g. oil, steel, etc) she needed to continue to prosecute her China campaign, and so looked southward and west towards the East Indies and Indochina in order to get the oil and minerals she needed for her war. She viewed the U.S. Pacific Fleet at Pearl Harbor as a direct threat to those ambitions. In a nutshell, that’s pretty much it.

Joriental is right with “There has never been a Housing ministry in Japan. And the population issue and the war doesn’t link directory.”

One factor that many don’t think is Oil. Japan being a small island and USA at the time the #1 distributor of Oil and control much of the Pacific’s oil sites. To continue as a country, japan had to do something to get oil for its new Industrial society.

* It had a huge effect. Japan wanted to become far superior to any country around them but they didn’t have the natural resource to do it. China wasn’t going to trade with a enemy so their only option was to attack China and try to take them over. The US also cut Japan off. The US was neutral at that point but they had always favored the allies and wanted them to win. But they didn’t have the public’s support because they felt the war didn’t concern them and staying neutral was the best route. Pearl Harbor changed that. Japanese Imperialism was the main reason. Technically Japan didn’t really enter WWII as it was already at war with China since 1937, Japan also signed treaties with Germany, It attacked America because America cut off its oil BECAUSE of their ongoing war and massacare of China.

Germany declared war on America shortly after Pearl Harbor, Thus entering America into the War, and since Japan and America were already enemies, It automatically entered WWII Can use below as intro.

The Second Sino-Japanese War (July 7, 1937 – September 2, 1945), called so after the First Sino-Japanese War of 1894–95, was a military conflict fought primarily between the Republic of China and the Empire of Japan. From 1937 to 1941, China fought Japan with some economic help from Germany (see Sino-German cooperation), the Soviet Union (1937–1940) and the United States (see American Volunteer Group). After the Japanese attack on Pearl Harbor (1941), the war merged into the greater conflict of World War II as a major front of what is broadly known as the Pacific War. The Second Sino-Japanese War was the largest Asian war in the 20th century.[8] It also made up more than 50% of the casualties in the Pacific War if the 1937–1941 period is taken into account. Although the two countries had fought intermittently since 1931, total war started in earnest in 1937 and ended only with the surrender of Japan in 1945. The war was the result of a decades-long Japanese imperialist policy aiming to dominate China politically and militarily and to secure its vast raw material reserves and other economic resources, particularly food and labour.

Before 1937, China and Japan fought in small, localized engagements, so-called “incidents”. In 1931, the Japanese invasion of Manchuria by Japan’s Kwantung Army followed the Mukden Incident. The last of these incidents was the Marco Polo Bridge Incident of 1937, marking the beginning of total war between the two countries. Initially the Japanese scored major victories in Shanghai, and by the end of 1937 captured the Chinese capital of Nanking. After failing to stop the Japanese in Wuhan, the Chinese central government moved to Chungking in the Chinese interior. By 1939 the war had reached stalemate after Chinese victories in Changsha and Guangxi. The Japanese were also unable to defeat the Chinese communists forces in Shaanxi, which performed harassment and sabotage operations against the Japanese. On the 7th of December 1941 the Japanese attacked Pearl Harbor, and the following day (December 8) the United States declared war on Japan. Japan surrendered on September 2, 1945. (( Read the article below – will help in answering questions))) Overview

Although most Americans were shocked by the Japanese attack on Pearl Harbor on December 7, 1941, the outbreak of war between the two countries came as no surprise to most observers of international affairs. Indeed, the war could be seen as the culmination of tensions between the two countries that can be traced back to 1915, when Japan issued its so-called “Twenty-One Demands” on China. These demands, presented as an ultimatum to the Chinese government, would have amounted to giving Japan a privileged status in certain parts of the country. This was in direct conflict with the stated policy of the United States toward China—the famous “Open Door,” in which all countries were to respect Chinese sovereignty and enjoy equal access to Chinese trade. Exacerbating the situation were the economic problems of Japan in the late 1920s, made worse by the Great Depression which swept the industrialized world in the early 1930s.

As an island country with few natural resources, Japan was dependent on international trade, which was disrupted by the economic crisis. Moreover, Japan was overpopulated, but other countries—most importantly the United States—closed the door to Japanese emigrants. Increasingly Japan’s military leaders became convinced that only through domination of China could they solve their country’s problems. Japan’s excess population could be settled in the largely undeveloped Chinese province of Manchuria, while Japanese industry could be revitalized through control of China’s import market. Therefore the 1930s saw a steadily increasing campaign of Japanese aggression in China, beginning with the invasion of Manchuria in 1931 and culminating in the outbreak of full-scale war between the two powers in 1937. Each instance of aggression resulted in denunciations from the United States, but the administrations of the time—that of Herbert Hoover until 1933, and of Franklin D. Roosevelt thereafter-understood that there was no will on the part of the American public to fight a war in East Asia.

Therefore U.S. policy by the late 1930s consisted of nothing more than a refusal to recognize Japanese conquests, limited economic sanctions against Japan, and equally limited military and economic assistance for China. Nevertheless, the Japanese bitterly resented even these halfway measures, and when their war against China bogged down in 1939 they blamed outside interference for the stubborn refusal of the Chinese to submit to their terms. They sought a way to prevent foreign aid from reaching China, and to replace the foreign resources that they could no longer acquire due to American economic sanctions. In Germany’s lightning victories of April – June 1940 Tokyo believed it had found the answer to both problems. In Southeast Asia and the South Pacific lay a number of territories controlled by France, the Netherlands, and Great Britain, which none of those countries appeared capable of defending. If they were to fall into Japanese hands Tokyo’s strategic dilemma, it seemed, could be solved.

After concluding an alliance with Germany in July 1940, Japan pressured the French government into allowing Japanese troops to occupy the northern part of French Indochina. In the following year Japanese forces occupied the entire country. The U.S. government met this latest series of aggressive moves with a steadily escalating campaign of economic sanctions, so that by late summer of 1941 Japan was no longer able to purchase any materials from the United States. This was a tremendous blow for many reasons, but particularly because Japan was almost completely dependent upon U.S. imports for its supply of oil. Without oil, of course, Tokyo would have to abandon its war against China—a humiliation that no Japanese leader would accept. The result was a frenzy of diplomatic maneuvering between Japan and the United States throughout the second half of 1941. However, Tokyo knew that time was running out; if the United States failed to drop its trade sanctions Japan would run out of oil within months. Therefore Japan’s leaders made a fateful decision-if no settlement could be reached with Washington by the end of November there would be war.

Moreover, the Japanese naval command concluded that this war must begin with the most devastating attack possible against the United States—an air strike, using carrier-based planes, against the U.S. Pacific Fleet at Pearl Harbor. The result, of course, would be a four-year conflict that, in the end, would prove disastrous for Japan. In this four-lesson curriculum unit, students begin by exploring through contemporary documents the rise of animosity between the United States and Japan beginning in World War I and continuing over the next two decades . They consider next through primary source documents and an interactive timeline the overall principles which underlay both Japanese and American foreign policy in the mid- to late-1930.

Students turn then to examine through primary documents and maps why Japan embarked on its policy of aggression against China, also considering the U.S. response to this new policy, and how it contributed to war between the United States and Japan. Finally they are asked to put themselves in the shoes of U.S. and Japanese diplomats in the final months of 1941, desperately trying to reach a settlement that will avoid war. Through the use of primary documents and an interactive map and timeline, they will consider whether there was any reasonable chance of preventing the outbreak of World War II in the Pacific

Lesson 1
While the Japanese attack on Pearl Harbor on December 7, 1941, came as a shock to Americans, there had long been talk of the possibility that a war might occur between the United States and Japan. Here was a case of two emerging world powers, both of whom with interests in China, increasingly coming into contact during a period when the powers that had traditionally dominated the region-the European colonial powers—were falling into decline. The United States was engaged in a lucrative trade with China, trade which was protected from bases in the Philippines, which had been a U.S. possession since 1898. Japan, on the other hand, had emerged victorious in two wars (the Sino-Japanese War of 1894 and the Russo-Japanese War of 1904-05) that left the country in possession of an empire that included Taiwan and Korea, as well as substantial interests in the Chinese province of Manchuria. U.S. policy in China was based on the principle of the “open door”—that is, all countries were to have equal opportunities for trade and investment opportunities in China.

However, this principle faced a severe challenge during World War I. Japan, having entered the war on the side of the Allies, captured the Chinese province of Shantung, which had been a German colony. Tokyo in 1915 then issued a set of “Twenty-One Demands” on China, which included not only Chinese recognition of Japanese ownership of Shantung, but acceptance of a Japanese sphere of influence over much of northern China. After much protest from the United States (as well as, needless to say, from China), Tokyo moderated its demands somewhat, and in the Lansing-Ishii Agreement of 1917 the United States and Japan pledged to oppose “the acquisition by any government of any special rights or privileges that would affect the independence or territorial integrity of China or that would deny to the subjects or citizens of any country the full enjoyment of equal opportunity in the commerce and industry of China.” Soon after the end of World War I the United States sponsored the Washington Conference of 1921-1922, to which the Japanese sent a delegation. A number of agreements were signed at Washington, but two bear mentioning here.

The first was the Five-Power Pact in which the United States, Great Britain, Japan, France, and Italy agreed to reduce the size of their navies. Britain and the United States were to have the world’s largest fleets, while that of Japan would be limited to three-fifths that of the British and the Americans. At Washington the Japanese delegation also signed the Nine-Power Pact , in which the signatories agreed to respect China’s sovereignty and independence, and renounced any desire to seek “special rights or privileges” in China. While these treaties may have appeared to settle differences between Japan and the United States, neither one really addressed the issue of Japanese ambitions. Japan in the 1920s faced overpopulation and economic crisis. Moreover, America’s trade and immigration policies—which by the 1920s had raised tariffs to unprecedented levels, and had cut off all possibility of Japanese immigration to the United States—were viewed as direct threats to Tokyo’s interests.

All of this strengthened the hand of elements in the Japanese Army and Navy, who claimed that the nation’s problems could only be remedied by the conquest of Manchuria, both as a source of raw materials for Japan’s factories and as area to be settled by Japanese colonists. Japanese naval officers also objected to the Five-Power Pact, claiming that national honor demanded a navy equal in size to that of the United States or Great Britain. Through the rest of the 1920s the government in Tokyo continued to seek good relations with the West. However, the army and navy were growing increasingly restless as Japan’s economy steadily declined through the decade. Finally, concluding that the government would not act, officers of the Japanese Army stationed in southern Manchuria decided to force the issue. In September 1931, outside the town of Mukden, a small group of officers secretly blew up a length of track belonging to a Japanese-owned railway.

Then, after blaming the sabotage on Chinese “bandits,” the Japanese Army moved to occupy all of Manchuria. Japan’s civilian government had not authorized this operation, but after an unsuccessful attempt to restrain the army in Manchuria the leaders in Tokyo decided to go along with it. The Japanese invasion of Manchuria was a clear violation of both the Nine-Power Pact and the 1928 Kellogg-Briand Pact , also signed by Japan, in which the signatories agreed to renounce war “as an instrument of national policy.” The international response, therefore, was one of alarm. Nevertheless, given that most of the industrialized world was in the grip of the Great Depression, no concrete steps were taken to block this act of aggression. U.S. Secretary of State Henry Stimson responded with a policy of “non-recognition”—that is, he announced that the United States would not recognize “any situation, treaty, or agreement” that impaired “the sovereignty, the independence, or the territorial and administrative integrity of the Republic of China.”

In late 1932 a commission formed by the League of Nations officially branded the occupation of Manchuria an act of aggression, but took no further action. All of this, of course, meant that Japan believed that it could proceed with its plans for China without foreign interference. In March 1932 Tokyo announced the creation of an “independent” state of Manchukuo, to be ruled by the former Chinese Emperor (who had been deposed twenty years earlier, at the age of five). That December the Japanese Army invaded the neighboring Chinese province of Jehol, which was promptly declared part of Manchukuo. The following year Japan withdrew its delegation from the League of Nations. The situation in Asia was rapidly growing dangerous, although few in the United States recognized this fact. One of the few who did was Joseph Grew, U.S. ambassador to Tokyo. As he put it in an August 13, 1932 letter to Secretary of State Stimson, the Japanese military “has been built for war, feels prepared for war and would welcome war. It has never yet been beaten and possesses unlimited self confidence. I am not an alarmist but I believe that we should have our eyes open to all possible future contingencies. The facts of history would render it criminal to close them.” Lesson 2

By the end of 1933 Japan had become almost entirely estranged from much of the rest of the world, thanks to the 1931 invasion of Manchuria (and its subsequent re-creation as the puppet state of Manchukuo) and the country’s withdrawal from the League of Nations. However, Tokyo’s greatest fear was the spread of Soviet influence in East Asia, and therefore in November 1936 Japan joined Germany in signing the Anti-Comintern Pact, in which the two powers pledged to cooperate in fighting international communism. More important, however, were efforts by Japan’s government to create a Japanese-dominated “autonomous region” in China north of the Great Wall to serve as a buffer against possible Soviet expansion into East Asia. Although Tokyo’s ambitions caused alarm among the Chinese, for the first few years the Chinese government at Nanking showed little willingness to resist Japan’s growing power in the country’s northern provinces. Indeed, China’s leaders seemed far more interested in fighting Chinese Communists, who were engaged in a continual campaign of subversion.

However, this all changed in December 1936, when Nanking abruptly changed course and signed an agreement with the Communists; from now on, both sides pledged, they would cooperate against the common threat of Japanese imperialism. Alarmed at this turn of events, the government in Tokyo began preparations for war, and after fighting broke out at the Marco Polo Bridge, just outside Peking, in July 1937 the Japanese army launched a full-scale offensive. Within a few weeks the Japanese had captured the Chinese cities of Peking, Tientsin, and Shanghai, and were advancing rapidly toward the capital of Nanking. Given that the United States had considerable trading and missionary interests in China, the Sino-Japanese War could not help but attract attention from Washington. President Franklin D. Roosevelt wasted no time in branding Japan as an aggressor, yet he did very little in practical terms to hinder Japan’s war effort. After all, in 1937 domestic affairs were still very much the president’s highest priority, so he settled for a policy that involved sending small amounts of aid to China and imposing very limited economic sanctions against Japan.

However, when in December 1937 Japanese aircraft attacked and sank the American gunboat U.S.S. Panay in the Yangtze River, the administration responded more forcefully, demanding (and receiving) a formal apology and indemnity from Tokyo . Roosevelt’s policies in East Asia were not without their critics, the most important of whom was Joseph Grew, the U.S. ambassador to Tokyo. In a letter to the Secretary of State he recommended that the United States either had to threaten to use force against Japan (which, in order to be credible, would require a serious increase in the size of the American armed forces), or to stay out of the Sino-Japanese conflict altogether. The administration’s policy of moral denunciation, limited assistance to China and economic pressure on Japan, he warned, would not deter Tokyo-it would only anger the Japanese and drive them toward more extreme measures. Indeed, the U.S. response did not bring an end to Japanese aggression in China, but it did encourage the Chinese government in holding out against Tokyo’s demands.

The Japanese army continued its advance, seizing Nanking (followed by an orgy of looting and rape which shocked the world) in December 1937. Tsingtao, Hankow, and the port cities of South China (the most important of which was Canton) fell over the course of 1938. Yet the Chinese government refused to surrender, moving its capital west to Chungking, far in the interior of the country. All of this posed a serious problem for Japan. While its army had won every battle against the Chinese, it was clear that there were not enough Japanese troops to overrun a country as large as China. Indeed, by late 1938 there were not even enough men to impose an effective occupation over those parts of the country that they had conquered, so that a powerful Communist-led guerrilla movement was able to operate behind Japanese lines. By 1939, therefore, the offensive had run out of steam. Tokyo concluded that it could only win the war by cutting China off from its foreign sources of support, and by seeking new resources to fuel its war effort. This, however, would mean expanding the scope of the war, and potentially escalating U.S.-Japanese tensions into a full-scale crisis. Lesson 3

Background
By 1940 the Japanese war against China—euphemistically referred to in Tokyo as the “China Incident”—was in its fourth year, and victory remained nowhere in sight. The Japanese Army seemed to win every battle, but the Chinese had ample room for retreat. China’s capital was now located far to the West, in Chungking, and the Chinese were receiving substantial aid from abroad, mostly from the United States and the Soviet Union. The Japanese occupied the wealthiest, most developed parts of China, but they barely had enough men to garrison their conquests, let alone penetrate deeper into Chinese territory. This grim situation explains why Tokyo looked upon the German victories of April-July 1940 with such excitement. In a matter of months Hitler’s armed forces had conquered Denmark, Norway, Belgium, the Netherlands, Luxembourg and France. Great Britain remained without great-power allies, with only the English Channel standing between Britain and the might of the German Army.

The Japanese were less interested in Europe per se than they were in Europe’s possessions in Asia. The British colonies of Burma and Hong Kong, and the French colony of Indochina (modern-day Vietnam, Laos, and Kampuchea) were all known for being conduits for U.S. aid to Chungking. In addition, several European possessions in Southeast Asia were rich in raw materials that were vital to Japan’s war effort—particularly the Netherlands East Indies, home to vast oil reserves. The opportunities presented by recent developments were summarized in a document called “General Principles to Cope with the Changing World Situation,” which Japanese military and government leaders agreed to in late July 1940. In an effort to bring victory in the “China Incident,” Tokyo would seek better relations with Germany, and would pressure the beleaguered British into preventing supplies bound for China from passing through their colonial possessions. Most importantly, Japan would launch a “southern advance” aimed at bringing the natural resources of Southeast Asia under its control. Japan’s leaders recognized that all of this would involve a “natural deterioration of relations with the United States,” but this was a chance well worth taking. Tokyo wasted little time in putting its “General Principles” into action.

Under pressure from Japan, Great Britain agreed to close the “Burma Road,” the most important avenue for U.S. aid to China. In September Japan joined Germany and Italy in signing the Tripartite Pact—often referred to as the Axis Pact—in which each signatory promised assistance in case any of the three found itself at war with any country “not involved in the European war or in the Chinese-Japanese conflict”; which, in practice, meant primarily the United States. Finally, Tokyo began to push into French Indochina, occupying the northern half of the country in September 1940 and the southern half in July 1941. The critical question in Tokyo was how the United States would respond to all this. The Roosevelt administration was indeed alarmed, particularly by the Tripartite Pact and the occupation of Indochina. At the same time, the president was hampered by the fact that the American people had no desire to go to war. Moreover, Asia was not Roosevelt’s highest priority in the summer and fall of 1940—the possibility of a German conquest of Great Britain appeared far more threatening for American national security.

Therefore the U.S. responded with the same approach that it had used toward Japanese aggression that it had since 1937—economic sanctions. After the occupation of northern Indochina Secretary of State Cordell Hull announced an embargo on sales of scrap iron and steel to any country outside the western hemisphere except Great Britain. Since Japan was one of the largest buyers of this commodity, Tokyo knew immediately that the new policy was meant as an anti-Japanese measure. The real blow, however, came in reaction to the Japanese occupation of southern Indochina. On July 26, 1941, President Roosevelt issued an executive order freezing all Japanese assets in the United States. This meant, in practice, that Japan could purchase nothing from the United States. While this was bad news for Tokyo for many reasons, the most devastating effect of the freeze was that it cut off Japan from its leading supplier of oil. Without oil, of course, the Japanese war effort in China could not continue.

Therefore, unless trade relations were restored with the United States, or the oil reserves of the Netherlands East Indies could be brought under Japanese control, Tokyo would be faced with the prospect of a humiliating withdrawal from China. It was therefore with a certain sense of desperation that Japan’s leaders met at a conference, with the emperor himself in attendance, in early September 1941. All present agreed that the situation was grave, and that Japan’s military power would begin to deteriorate rapidly in a few months. Therefore, while efforts to reach some sort of compromise with the Americans would continue, the country had to prepare for war in the near future.

The “southern resource area,” particularly the Dutch East Indies and the British colony of Malaya, had to be secured quickly, and this would certainly mean war with Great Britain. Under those circumstances, would the United States remain neutral, or come to Britain’s aid? There was no way of knowing for certain, but the U.S. Navy was the only force in the region capable of interfering with Japan’s plans in any serious way. If Tokyo tried to fight only the British, the Americans, striking from the Philippines or from Pearl Harbor, could inflict major damage to Japanese forces. The answer seemed clear—if there were to be war, the U.S. Pacific Fleet had to be neutralized Lesson 4

At an Imperial Conference in Tokyo in early September 1941 Japan’s military and civilian leaders reached a critical decision. During the previous month President Roosevelt, reacting to the Japanese occupation of southern Indochina, issued an executive order freezing of all Japanese assets in the United States. Similar orders were soon issued by Great Britain and the Netherlands. The most dramatic effect of this order was that Japan would henceforth be unable to purchase oil from any of its primary suppliers. Tokyo’s oil reserves were dwindling, and without access to foreign oil the Japanese military effort against China would have to be called off. Therefore the politicians and officers who gathered in the emperor’s presence in early September agreed that while a diplomatic settlement should still be pursued, the country had to begin preparations for a war with the United States and Great Britain, to begin no later than December 1941. A diplomatic solution, however, seemed unlikely, given the four issues that divided the two powers.

The first involved China. Japan’s war against China had by this time been going on for four years, with no end in sight. Although the Japanese Army controlled the richest and most populous parts of China, the regime in Chungking refused to surrender, and by the end of 1939 the Japanese advance had been bogged down in the Chinese countryside. Tokyo believed that U.S. assistance to China was encouraging Chungking’s intransigence; surely, Japan’s leaders argued, if the United States stopped sending aid, China would give see that there was no point in continuing the war. The Roosevelt administration, on the other hand, saw the war as a simple matter of Japanese aggression, and believed that the termination of U.S. aid would amount to “appeasement.” The second area of contention was the French colony of Indochina, which Japanese troops had occupied in two stages during 1940 and 1941. By holding Indochina Japan could close one of the routes by which U.S. aid was reaching China.

More importantly, it would serve as a useful staging area for what Tokyo called the “southern advance”—in other words, possible military operations against the Dutch East Indies, the British colonies of Burma and Malaya, and, if necessary, the U.S.-controlled Philippines. Washington also recognized the strategic value of Indochina, and therefore was insistent that the Japanese withdraw from the colony. A third source of tension was the Tripartite Pact, which Japan had concluded with Germany and Italy in September 1940. Each of the three signatories to the pact promised to “assist” any of the others if they were attacked by another power. By late 1941 a war between the United States and Germany appeared to be a definite possibility. What would Tokyo do under those circumstances? Finally there was the issue of international trade. Japan, of course, was dependent on foreign trade for a number of critical resources, particularly oil. The United States, therefore, had made economic sanctions the cornerstone of its policy toward Tokyo. Indeed, the Roosevelt administration believed that it was the only real leverage that America had in Asia, given that there was little public support for military action.

Thus while it was vital for the Japanese that normal trade relations be restored, Washington was unlikely to abandon sanctions without major concessions from Tokyo. Because these differences ran so deep, the diplomatic maneuverings of the next few months proved fruitless. Finally, on November 20, the Japanese made a final attempt at a “modus vivendi” (Japanese Draft Proposal, November 20, 1941)—in other words, a short-term attempt to settle immediate problems—in which they offered to withdraw all of their forces from Indochina in return for a resumption of oil shipments from the United States. Six days later Secretary of State Hull responded with a counter-offer (Proposed Basis for Agreement, November 26, 1941) that shocked Japan’s leaders. The United States would normalize trade with Japan only if Tokyo withdrew its forces not only from Indochina, but from China as well.

This was a condition that the Japanese military would never accept. The Japanese quickly concluded that the United States was not interested in serious negotiations, and moved forward with their plans for war. Why did the United States take such a hard line? Unbeknownst to the Japanese, American code breakers had by this time deciphered Tokyo’s diplomatic code. President Roosevelt and Secretary of State Cordell Hull, therefore, both knew that Japan had placed a deadline of November 29 on negotiations. While it remained unclear what would happen after that date, it was a safe bet that the Japanese were planning on launching an attack—probably against the Dutch East Indies or the Philippines. Roosevelt concluded from this that it was the Japanese who were no longer serious about finding a peaceful solution to the two countries’ differences. Since Tokyo had already decided on war, it was better to take a stand on principle. Whether or not the Japanese were still genuinely interested in peace in late November remains a subject of debate. Roosevelt was clearly wrong, however, about where the Japanese would strike.

On November 26—even before the deadline the government set for negotiations—a large task force, made up of four aircraft carriers and their escorts, sailed from Tokyo Bay. Over the next two weeks Washington sent repeated warnings to all commands to expect a Japanese attack. It came at Pearl Harbor on Sunday, December 7. Two waves of carrier aircraft struck the U.S. Pacific Fleet as it lay at anchor, and by the time the raid had ended four U.S. battleships had been sunk and three others were damaged. Nearly 200 aircraft were destroyed on the ground, and more than 2,400 people were killed. (More detailed information about the attack is available at National Geographic’s “Remembering Pearl Harbor”).

Later that afternoon the Japanese ambassador presented Secretary of State Hull with a statement (Memorandum, December 7, 1941) that placed the blame for the failure of negotiations between the two countries squarely on the shoulders of the United States. After reading it Hull claimed he had “never seen a document that was more crowded with infamous falsehoods and distortions.” The following day Roosevelt addressed a joint session of Congress, calling December 7 a “date which will live in infamy” and asking for a declaration of war against Japan. Congress wasted no time in doing so.