How did Japan grow into a world power before WWII?

Japan's Involvement in World War II

In September 1940, Japan signed the Tripartite Pact with Nazi Germany and Fascist Italy, in which they agreed to assist one another should any of them be attacked by a country not already involved in the war. ... The United States declared war one day later.

the right answer is the end of world war ii

after the end of a global wwii all the nations involved, in an attempt to create an organization to maintain world peace. this agreement would work settling international disputes via negotiation and arbitration instead of leading the issues escalate to another war.