The economic crises in the 1930s and the need for natural resources for the industries began Japan to look for territorial expansion. In 1931, Japanese soldiers seized Manchuria and converted it to a colony of Japan for several years.
Japan faced a shortage of natural resources.
Japan being an Island and mountainous region, did not have any natural resources. Japan relied on importing raw materials from its neighbouring countries. They felt that they need to conquer those territories, which could help them in building Japan into greatness. Japan fought and conquered territories in China and Korea to get resources.
The Japanese decided to attack pearl harbour.
The Imperial Japanese Navy during the beginning of WWII was growing powerful and exercise its strength in the Pacific Ocean. The United States make some interference to protect Southeast Asia from Japan. The Japanese decided to attack pearl harbour as a reply to show their power in the Pacific Ocean.
