The document discusses the historical background and formation of the Brussels Treaty Organization and Western European Union (WEU). The Brussels Treaty was signed in 1948 by France, the UK, Belgium, the Netherlands, and Luxembourg to promote economic recovery and collective self-defense in Western Europe following World War 2. This was later expanded in 1954 to form the WEU, an intergovernmental military organization with 10 member states that was eventually absorbed into NATO for defense purposes. The WEU was formally abolished in 2010 with the Lisbon Treaty which transferred its mutual defense clause to the European Union.