The following were equally important reasons why the Japanese attacked Pearl Harbor in December 1941:

Worsening US-Japan relations
Desire to control Southeast Asia
Destruction of the US Pacific fleet

Do you agree with this statement? [13]


Worsening relations between Japan and the US was certainly one reason for Japan to attack Pearl Harbor. Ever since Japan started to expand into China, the US habecome more wary of Japan's ambitions. As Japan imported most of its raw materials from the US, the US began to place embargoes on Japan to check its aggression. This did not affect Japan's war efforts greatly as critical resources such as oil continued to be sold to Japan. It was only when Japan took over French Indo-China in 1940 that the US placed an embargo on the sale of oil to Japan. This brought US-Japan relations to a new low. Negotiations were conducted to resolve the situation but they were unsuccessful. As a result, Japan was prepared for war against the US.

The desire to control Southeast Asia was linked to the need to acquire oil. With the supply from the US cut off, Japan needed to take over Indonesia, which was rich in oil, in order to continue the war efforts. To do so would require Japan to take over the whole of Southeast Asia, including the Philippines, which the Americans had colonised. An attack on the Philippines would lead to the Americans seeking reinforcements from their base at Pearl Harbor. The arrival of these reinforcements would effectively prevent Japan from controlling Southeast Asia quickly. Therefore, it was necessary for the Japanese to attack Pearl Harbor at the same time as they were attacking Southeast Asia.

The destruction of the US Pacific Fleet was seen as a critical step to ensure Japan's dominance of the Pacific region. If the Pacific Fleet was destroyed, the Japanese believed that US confidence would be severely affected. At the same time, the US would need a long time to rebuild their strength before they would confront the Japanese. By then, Japan would have secured the areas it needed. The successful destruction of the US Pacific Fleet would also demonstrate Japan's rise as a world power and not to be underestimated by the West.