Combined means that forces of two or more nations are involved.

The CJTF initiative was designed to provide flexible command arrangements within which allied forces could be grouped to take on a wide variety of missions beyond the borders of Alliance countries. Specifically, the concept is designed for the following purposes:

- to give NATO’s force and command structure sufficient flexibility to respond both to Alliance security requirements and to new missions.
- to facilitate the use of NATO forces and command structures for operations run by the Western European Union (WEU), which is the defence organisation chosen as the framework for constructing a “European pillar” within NATO. Its membership includes only European countries. Working within the framework of the WEU, European nations would be able to undertake missions with forces that are “separable but not separate” from NATO. Gradually, it is intended that the role played by the WEU will be assumed by the European Union (EU).
- to facilitate the participation of non-NATO Partner countries in operations, exercises and training which take place in the framework of the Partnership for Peace programme of cooperation.

Following the January 1994 Brussels Summit meeting, NATO member countries began the difficult job of turning agreements in principle on the adaptation of the Alliance to the post Cold War world into programmes of action. One of their important tasks was to give effect to the decision to strengthen the European Security and Defence Identity (ESDI) within the framework of the transatlantic Alliance. At critical meetings in Berlin in June 1996, NATO Foreign and Defence Ministers agreed on significant new steps which would meet this requirement. In particular, the Allies approved the implementation of the CJTF concept, along with a series of agreements designed to create the basis for enabling Europe to develop its own “European Security and Defence Identity” within NATO. The CJTF concept has already been tested in several Alliance exercises. Alliance operations, such as the peacekeeping role which NATO has undertaken in Bosnia and Kosovo, could be conducted in the future through CJTF headquarters. Implementation of the concept will also make it possible for the European Allies to take responsibility for future military operations in which the Alliance as a whole is not involved, with the support of NATO’s military capabilities. Under the agreements reached, NATO assets and capabilities would be made available for future military operations commanded by the Western European Union (WEU). Decisions would be made regarding these arrangements by consensus, on a case-by-case basis.