Question

Germany, Italy, and Japan formed the tripartite pact in part because they:

Answer 1

The Pact provided for mutual assistance should any of the signatories suffer attack by any nation not already involved in the war. This formalizing of the alliance was aimed directly at “neutral” America–designed to force the United States to think twice before venturing in on the side of the Allies.

Answer 2

They wanted to support one another in conquering Europe and Asia.

Step-by-step explanation:

Germany, Italy, and Japan all were countries that happened to share a ruling philosophy based on aggressive territorial expansion. So it seemed like a good idea, since Germany and Japan were allies more than once throughout history, that they would come out with an agreement to stay out of each other's business.