Why did japan get involed in World War 2?

Answer 1

There are a number of factors involved, some rooting back almost 100 years, Japan as nation state really came into being after the Meiji restoration in 1867, which began the process that ended its long history of feudal wars and warlords. As part of that movement , Japan began to quickly industrialize and establish itself as a legitimate power, indeed by the early 1900's it took on Czarist Russia and defeated it sounded both on land and at sea. This created a growing sense of nationalism at home and coupled with a system of emperor worship and militarism made Japan a very aggressive nation. It saw its future in industrialization and expansion but Japan being an island did not have the resources to support this. So the Japan took steps to secure raw material by first occupying Korea and setting up a puppet state in Manchuria (modern day NE China). It continued this pattern of expansion into many other countries and eventually launching an invasion of China proper after using a staged attack on Japanese troops as provocation much like Hitler's invasion of Poland (see Marco Polo Bridge Incident). This cause widespread international condemnation and the United States decided to cut off oil to Japan as a result. Realizing that without oil the Japanese war effort would grind to a halt, the Japanese Navy decided to gamble and expand the war. Knowing that this would lead to conflict with the US, it planned the infamous attack on Pearl Harbour, launching the bloody war in the Pacific.