International
North Atlantic Treaty Organization, the collective-defence alliance Finland joined in 2023.
The North Atlantic Treaty Organization (NATO) is an intergovernmental military and political alliance established by the North Atlantic Treaty in 1949, with headquarters in Brussels. Its membership consists of North American and European states that have acceded to the treaty. NATO was founded to provide collective defense and security cooperation among its members, centered on the treaty's mutual-defense commitment, under which an armed attack against one member is considered an attack against all. The alliance maintains consultative bodies, an integrated command structure, and forces contributed by members, and it conducts joint planning, exercises, and crisis-management operations. Decisions are taken by consensus among member governments. NATO does not maintain a standing army of its own; it relies on forces and capabilities provided by member states.