On September 27, 1940, the Axis powers are formed as Germany, Italy and Japan become allies with the signing of the in Berlin. 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 鈥渘eutral鈥 America鈥攄esigned to force the United States to think twice before venturing in on the side of the Allies.
The Pact also recognized the two spheres of influence. Japan acknowledged 鈥渢he leadership of Germany and Italy in the establishment of a new order in Europe,鈥 while Japan was granted lordship over 鈥淕reater East Asia.鈥
A footnote: There was a fourth signatory to the Pact鈥擧ungary, which was dragged into the Axis alliance by Germany in November 1940.