Final answer:
The alliance of Germany, Italy, and Japan during World War II was known as the Tripartite Pact. This pact aimed to provide mutual defense and further expansion of their empires.
Step-by-step explanation:
The alliance of Germany, Italy, and Japan during World War II was known as the Tripartite Pact. This alliance was signed in September 1940 and aimed to provide for mutual defense and further expansion of their empires. The pact stipulated that any of the three powers would declare war on a neutral country that declared war on one of the others.