The Japanese had been engaged in a policy of expansionism ever since the 1930s, with the invasion of Manchuria in China. This was part of an attempt to create a vast East Asian empire that would, it was hoped, allow Japan to compete on the international stage with other great...
The Japanese had been engaged in a policy of expansionism ever since the 1930s, with the invasion of Manchuria in China. This was part of an attempt to create a vast East Asian empire that would, it was hoped, allow Japan to compete on the international stage with other great powers such as the United States and the Soviet Union.
Although Western powers were understandably wary of what the Japanese were up to, it wasn't until their strategic interests were directly threatened by Imperial Japan that they began to fight the Japanese.
In December 1941, Japanese expansionism led directly to attacks on the British colonies of Malaya, Hong Kong, and Singapore as well as Thailand. All this happened not long before the devastating attack on Pearl Harbor.
Tensions over Japanese expansionism had been building over some time, and the United States, along with other countries such as Australia, Great Britain, and the Dutch government in exile sought to discourage further Japanese expansion by implementing a tough embargo that denied them vital raw materials.
It was largely in response to this embargo that the Japanese launched their coordinated attacks. The general idea was to seize as many raw materials, especially the oil that the Japanese military desperately needed, from conquered territories in order to offset the losses caused by the embargo.
But the Japanese were motivated by more than just a need for raw materials. They had long since entertained visions of building an East Asian empire in order to attain the great power status to which they believed they were entitled.
At some point, this would involve direct clashes with the strategic interests of the Western powers, including the United States. As America had extensive interests in the Pacific, it was virtually inevitable that Japanese expansionism would lead to a war in this part of the world.