koossusjõududest

Koossusjõududest is the Estonian term used to describe military forces formed by two or more states acting together under a common command for a particular operation. The word combines koos, meaning together, and jõud, meaning forces, with the suffix -udest marking a genitive plural reference to the coalition's forces. In Estonian military and historical writing, koossusjõududest generally denotes multinational coalitions assembled for a mission rather than a single nation's armed forces.

Characteristics commonly associated with koossusjõududest include a formal agreement outlining tasks and authority, a joint or integrated command structure, interoperability arrangements for equipment and communications, and shared rules of engagement and objectives. They may be led by a formal alliance framework such as NATO, a United Nations mandate, or a regional coalition, and they often involve multinational staff and contingents.

Use of the term appears in discussions of both historical and contemporary operations, from World War II era Allied coalitions to modern international missions where Estonian forces participate as part of multinational coalitions. The concept reflects the shift from national-centric defense to collaborative security mechanisms in international affairs.

See also: Allied forces, Coalition warfare, Estonian Defence Forces, NATO missions, United Nations peacekeeping.