Summarize why Japan turned its imperialist ambitions toward Southeast Asia, and explain why they decided to launch a pre-emptive strike against the United States.

Answer 1

Consider the shortages that Japan had (being an island) and then consider how this would have alleviated those. Perhaps it was a shortage of resources. Its important that you reason through this and come up with possibilities.

Answer 2

The leaders of the Empire of Japan, particularly its military leaders, had come to believe that, in order for Japan to protect itself and become a world power like, for example, Great Britain, it would need raw materials that were not present in the home islands of Japan. The home islands, for instance, lacked sufficient supplies of coal and iron ore with which factories could produce the steel necessary to build modern warships. Therefore, in the minds of Japan's leaders, the only alternative was to conquer territories located overseas, territories that contained what the Japanese home islands lacked.

The Asian mainland, located a short distance to the west of the Japanese home islands was an obvious source for the resources that Japan lacked, so that, beginning in the late-19th century, Imperial Japan pursued a policy of conquest. The peninsula of Korea and the Island of Formosa were both seized and declared to be the possessions of the Japanese Empire. In 1931 the Japanese Army invaded and conquered the territory of Manchuria - at that time, a part of the Republic of China.

So far Imperial Japan had met with success. Large territories containing needed resources had been conquered quickly and easily. But Japan's next attempt at conquest would be very different. In 1937 Japan went to war with the Republic of China. Japan's military leaders judged the Republic of China to be politically divided and militarily weak. They thought that the leader of the Republic of China would be forced to give up and would negotiate a peace treaty that would leave Japan in control of much of China. Instead, the Republic of China, despite suffering repeated defeats on the battlefield, continued to fight. Because of this, Japan was forced to send more and more troops to China in a war that seemed to have no end.

To complicate matters, the Western democracies - Great Britain, France, the United States, among others - objected to Japan's invasion of China. The longer the war in China went on, the more opposition from the Western Democracies grew. Ultimately, in the summer of 1941, Great Britain, the United States, and, importantly, the Netherlands (Holland), joined together to stop the sale of oil to Japan. Oil was critical to both Japan's economy and to conducting the war in China. Oil was needed to fuel the warships of Japan's Navy, the fuel used to power Japan's warplanes was produced from oil, as was the gasoline necessary for trucks and tanks. Japan had to gain control of a source of oil, otherwise, it would have to give up its attempt to conquer China.

The nearest source of oil was the colonies of the Netherlands (Holland) in southeast Asia, in what is today the country of Indonesia. At the time, these were known as the 'Dutch East Indies'. They contained large deposits of oil that the Dutch (the people of the Netherlands / Holland) were extracting and selling to customers around the world - but this no longer included Japan.

Circumstances seemed to favor Imperial Japan because, by 1941, the European nations that possessed colonies in Asia had suffered severe defeats in Europe. Both the Netherlands (Holland) and France had been defeated and conquered by Nazi Germany. As such, they were not in a position to effectively defend their colonies in Asia. Although Great Britain had not been overrun, the nation needed all of its resources to continue to fight against Germany, so little could be spared to defend Britain's Asian colonies in the face of a Japanese attack.

The only other major power that had the potential to interfere with Japan's conquest of the Dutch East Indies was the United States, which possessed its own colony in Asia - the Philippine Islands. Already, President Franklin Roosevelt had demonstrated that the United States would be prepared to fight if Japan sought to conquer Southeast Asia when he ordered the U.S. Pacific Fleet to be moved from San Diego, California, to Pearl Harbor in the Hawaiian Islands, placing it closer to the Philippines and closer to the Japanese home islands.

Instead of launching an invasion of the Dutch East Indies and then waiting for a response from the United States - a response that Japan felt was guaranteed to be a declaration of war against Japan - the military leaders of Japan decided that they should seek to eliminate, or at least severely cripple, the U.S. Pacific Fleet BEFORE they launched an invasion of the Dutch East Indies. By doing so, the U.S. Pacific Fleet would not be available to stop the Invasion of the Dutch East Indies (as well as the many other locations throughout Asia and the Pacific Ocean region that the Japanese intended to invade). This was the reason for the surprise attack on Pearl Harbor on 7 December, 1941.