The Western European Union (WEU; , UEO; , WEU) was the international organisation and military alliance that succeeded the Western Union (WU) after the 1954 amendment of the 1948 Treaty of Brussels. The WEU implemented the Modified Brussels Treaty. During the Cold War, the Western Bloc included the WEU member states and the United States and Canada as part of the North Atlantic Treaty Organization (NATO). At the turn of the 21st century, after the end of the Cold War, WEU tasks and institutions were gradually transferred to the European Union (EU), providing central parts of the EU's new military component, the European Common Security and Defence Policy (CSDP). This process was completed in 2009 when a solidarity clause between the member states of the European Union, which was similar (but not identical) to the WEU's mutual defence clause, entered into force with the Treaty of Lisbon. The states party to the Modified Treaty of Brussels consequently decided to terminate that treaty on 31 March 2010, with all the WEU's remaining activities to be ceased within 15 months. On 30 June 2011, the WEU was officially declared defunct. History Background The Treaty of Brussels was signed by the United Kingdom, France, Belgium, Luxembourg, and the Netherlands on 17 March 1948, establishing the Western Union (WU), an intergovernmental defence alliance that also promoted economic, cultural and social collaboration. The need to back up the commitments of the North Atlantic Treaty with appropriate political and military structures led to the creation of the North Atlantic Treaty Organisation (NATO). In December 1950 the parties to the Treaty of Brussels decided to transfer the headquarters, personnel, and plans of the Western Union Defence Organisation (WUDO) to NATO, whose Supreme Headquarters Allied Powers Europe (SHAPE) took over responsibility for the defence of Western Europe. The establishment of NATO, along with the signing of a succession of treaties establishing the Organisation for European Economic Cooperation (April 1948), the North Atlantic Treaty Organisation (April 1949), the Council of Europe (May 1949) and the European Coal and Steel Community (April 1951), left the Treaty of Brussels and its Western Union devoid of authority. 1954–1984: General dormancy The Western Union's founding Treaty of Brussels was amended at the 1954 Paris Conference as a result of the failure of the Treaty establishing the European Defence Community to gain French ratification: The General Treaty () of 1952 formally named the EDC