What is a command that operates under treaty or agreement between nations called?

A command that operates under a treaty or agreement between nations is referred to as a Combined Command. This term specifically denotes an organization formed by two or more nations working together under a unified command structure, typically to achieve shared military objectives. The concept emphasizes collaboration and coordination between allied forces, often established through formal agreements or treaties that outline the roles and responsibilities of participating nations.

This command structure contrasts with other types such as Joint Command, which typically refers to joint operations within a single nation’s military, or Unified Command, which can operate across different branches of service within one country, but not between multiple nations. Cooperative Command, while it suggests collaboration, is not a formal military term recognized in the same way as Combined Command within international military treaties.