Tripartite Pact 27 Sep 1940

• Mutual assistance should any of the countries suffer attack by any nation not already involved in the war
• Aimed directly at "neutral" America
  • Force the US to think twice before joining the Allies
• Recognised the 2 spheres of influence
  • Japan acknowledged "leadership of GR and Italy in the establishment of a new order in Europe"
  • Japan granted lordship over "Greater East Asia"

References

https://www.history.com/this-day-in-history/the-tripartite-pact-is-signed-by-germany-italy-and-japan