Week 26: Pearl Harbor

Why did Japan Attack Pearl Harbor?

Japan's actions from 1852 to 1945 were motivated by a desire to emerge as the dominant power in Asia.

For Japan, World War II grew from a conflict historians call the Second Sino-Japanese War. The Second Sino-Japanese War began in earnest in 1937 with a battle called the Marco Polo Bridge Incident. However, before this, there had been years of border clashes between the Japanese and the Chinese, having started with the 1931 Japanese invasion of Manchuria. So, to explain Japan's behavior in the years from 1941 to 1945, we have to explain why Japan invaded Manchuria in 1931, and in order to do this, we have to go back to 1853.

Before 1852, Japan was isolationist. Contact with the West was limited to trade with the Dutch in the city of Nagasaki—Westerners otherwise weren't allowed in the country, and Western influences were strongly discouraged. In 1853, Commodore Matthew C. Perry of the United States Navy steamed into what we now call Tokyo Bay. The Japanese told him to leave and go to Nagasaki and a short battle broke out. The letter was eventually presented and Perry returned a year later to sign the Convention of Kanagawa, a treaty that opened the Japanese ports of Shimoda and Hakodate to U.S. trade.

This opening to outside trade is the moment that modern Japanese history begins. The importance of Perry's missions to Japan in the 1850s really can't be overstated. While Japan had previously thought itself to be a strong country, Japan’s new openness destroyed this self-image. While Japan's isolation had allowed the Japanese to think that it remained a world power, the end of this isolation demonstrated the country’s weakness.

In 1868, a reform movement was launched to counteract this weakness, in what we now call the Meiji Restoration. The shogun was stripped of his power, which was then nominally placed back in the hands of the emperor but really into the hands of his advisers. In a very brief span of time, the medieval feudal system that had governed Japanese society for centuries was abolished, the military was reformed, and the country was put on the path to rapid industrialization. As part of this rapid leap into modernity Japanese citizens began to adopt Western-style dress while the military and governments recreated themselves along Prussian (that is to say, Germanic) lines.

The new Japanese government began to utilize the tools of colonization to acquire the raw materials their new industries required. The obvious target for Japanese imperialism was just across the Sea of Japan in Korea. By the 1890s, Korea was actually seen as a massive liability for Japan: It had not reformed as Japan had, and unlike China, it could feasibly be conquered. Additionally, the Korean peninsula is rich in iron and coal, which you need if you're a rapidly industrializing country in the 19th-century. Because Japan is not particularly rich in natural resources, it was advantageous for it to have colonies.

The problem was that Korea was a Chinese tributary state: The Korean king paid tribute to the Chinese emperor. While the Japanese could, and did, force the Koreans to sign some deeply unfair treaties, the peninsula remained free of the Japanese military. However, in 1894, China sent troops into Korea to help put down a rebellion, not notifying the Japanese before it did so. Japan also sent in troops to respond. Unsurprisingly, fighting broke out, leading to the First Sino-Japanese War from 1894-1895.

The Chinese lost the war, and they lost it badly. With the Treaty of Shimonoseki, Korea stopped paying tribute to China and effectively became a Japanese tributary state. The Japanese also gained the island of Taiwan as a colony, along with reparations and trading rights in several Chinese cities. Additionally, the Japanese gained the Liaodong Peninsula, from which several Western powers forced it to withdraw. Not that the Chinese were allowed to hold onto the Liaodong Peninsula either—the Russians leased it. This was the start of Japan's colonial empire, along with a rivalry with the Russians for influence in Korea and Manchuria.

This rivalry ended up leading to the 1904-1905 Russo-Japanese War. The Japanese emerged victorious from this conflict and were consequently seen as a great power. The Japanese walked away with the Liaodong Peninsula lease—formally, the Kwantung Leased Territory—along with substantial rights in Manchuria, most notably control over Manchuria's railroads. After the war, Japan officially made Korea a protectorate in 1905—Russia was in no position to contest that action—and subsequently annexed Korea in 1910.

In World War I, Japan entered on the side of the Allied Powers and picked off Germany's colonial empire in the Pacific Ocean as a reward for its involvement. This was probably the high-water mark of Japan's powers prior to 1945. However, during the interwar period, aggressively expansionist moves, though far from unheard of, started leaving sour tastes in the mouths of many nations. It wasn't simply a matter of geopolitics, either—most people in Europe really did not want another war, and those countries that seemed to be provoking said wars were given the stink eye. Because Japan hadn't suffered in the war the way that, say, France and Belgium had, the reluctance to engage in brinkmanship simply wasn't instilled the same way.

Also in the interwar period, the Republic of China started getting its act together. While the country had effectively collapsed into a patchwork of feuding warlords in the 1910s, the Kuomintang managed to get most of the south unified under its government before embarking on what is now called the Northern Expedition from 1926 to 1928. This also brought the north of the country under the control of the Nationalist government, which was set up in the city of Nanjing. Nationalist China still had issues, warlords among them, but by 1928 it was a much stronger state.

Japan viewed China's steps toward reversing the damage of the previous century as a threat to its control of Manchuria's railroads and of the Kwantung Leased Territory. Losing anything to China was seen as unacceptable to the Japanese government. To that end, in 1931, the Japanese invaded Manchuria to protect their interests in the railroad and the Kwantung Leased Territory. Japan subsequently set up a puppet state, Manchukuo, which nobody else recognized as a legitimate state. This isolated Japan, and it also meant a continuing series of border clashes with the Chinese. Eventually, in 1937, the Japanese provoked the Chinese into full-scale war with the Marco Polo Bridge Incident.

Had the Second Sino-Japanese War been a short one, the Japanese might have walked away with a result similar to the First Sino-Japanese War: a hugely favorable treaty and some land cessions. However, the Nationalist government didn't give in so quickly and would not agree to a negotiated peace with the sort of terms the Japanese government required to stave off a revolution.

To put it simply, the war pushed the Japanese economy and military to the limit. Japan's supplies of rubber, iron, and oil were pushed to the breaking point, and it had offended nearly every one of its former allies. Increasingly, the view in the international community was that it was a rogue state, which did not help it procure the materials needed to keep prosecuting the war in China. An attack on a U.S. boat on the Yangtze River alienated the U.S., as did widespread Japanese atrocities against the Chinese population, including the rape and murder of around 300,000 Chinese civilians in Nanking alone. Eventually, this led to embargoes on trade with Japan.

Japan desperately needed resources, and there were only two places to get them: Siberia and the South Pacific. The Imperial Japanese Army favored going after Siberia but were forced to abandon that strategy after the disastrous 1939 Battle of Khalkhin Gol. The Imperial Japanese Navy got its way, but it had to deal with the fact that the South Pacific was largely occupied by unfriendly states. Hence the simultaneous attacks on Pearl Harbor, Singapore, Hong Kong, the Philippines, and Malaya: The Japanese didn't want the Americans or the British to resist the Japanese scramble for rubber and oil. This turned out to be suicidal and a complete misreading of how the Americans would react to Pearl Harbor, but it was about 90 years in the making.

What led up to Pearl Harbor?

September 1940. The U.S. placed an embargo on Japan by prohibiting exports of steel, scrap iron, and aviation fuel to Japan, due to Japan's takeover of northern French Indochina.

April 1941. The Japanese signed a neutrality treaty with the Soviet Union to help prevent an attack from that direction if they were to go to war with Britain or the U.S. while taking a bigger bite out of Southeast Asia.

June 1941 through the end of July 1941. Japan occupied southern Indochina. Two days later, the U.S., Britain, and the Netherlands froze Japanese assets. This prevented Japan from buying oil, which would, in time, cripple its army and make its navy and air force completely useless.

Toward the end of 1941. With the Soviets seemingly on the verge of defeat by the Axis powers, Japan seized the opportunity to try to take the oil resources of Southeast Asia. The U.S. wanted to stop Japanese expansion but the American people were not willing to go to war to stop it.  The U.S. demanded that Japan withdraw from China and Indochina, but would have settled for a token withdrawal and a promise not to take more territory.

Prior to December 1941, Japan pursued two simultaneous courses: try to get the oil embargo lifted on terms that would still let them take the territory they wanted, and ... to prepare for war.

After becoming Japan's premier in mid-October, General Tojo Hideki secretly set November 29 as the last day on which Japan would accept a settlement without war.

The Japanese military was asked to devise a war plan. They proposed to sweep into Burma, Malaya, the East Indies, and the Philippines, in addition to establishing a defensive perimeter in the central and southwest Pacific. They expected the U.S. to declare war but not to be willing to fight long or hard enough to win. Their greatest concern was that the U.S. Pacific Fleet, based in Pearl Harbor could foil their plans. As insurance, the Japanese navy undertook to cripple the Pacific Fleet by a surprise air attack.

The Warnings

The U.S. had broken the Japanese diplomatic code and knew an attack was imminent. A warning had been sent from Washington, but it arrived too late.

Early warning radar was new technology.  Japanese planes were spotted by radar before the attack, but they were assumed to be a flight of American B-17s due in from the West Coast.  

Read the eyewitness account

The Attack

On December 7th 1941, on an otherwise peaceful Sunday morning on a beautiful Hawaiian island, the first wave of Japanese airplanes left 6 aircraft carriers and struck Pearl Harbor a few minutes before 8 AM local time.

In two waves of terror lasting two long hours, they killed or wounded over 3,500 Americans and sank or badly damaged 18 ships - including all 8 battleships of the Pacific Fleet - and over 350 destroyed or damaged aircraft.  At least 1,177 lives were lost when the Battleship U.S.S. Arizona exploded and subsequently sank.

However, they did not sink any of our Pacific aircraft carriers and they left most of the fuel that was needed to win the war in the Pacific.

In one stroke, the Japanese navy scored a brilliant success—and assured their ultimate defeat.