Western Union (alliance)

The Western Union (WU), also referred to as the Brussels Treaty Organisation (BTO),[1] was the European military alliance established between France, the United Kingdom (UK) and the three Benelux countries in September 1948 in order to implement the Treaty of Brussels signed in March the same year.[Note 1] Under this treaty the signatories, referred to as the five powers, agreed to collaborate in the defence field as well as in the political, economic and cultural fields.

Quick facts: Western Union, Status, Capital, Historical er... ▼

Western Union
1948–1954
Flag Badge
Status	Alliance
Capital	Fontainebleau, France London, United Kingdom
Historical era	Cold War
• Czechoslovak coup	21–25 February 1948
• Treaty of Brussels	17 March 1948
• WUDO established	28 September 1948
• Korean War breaks out	25 June 1950
• NATO absorbs WUDO	1951
• Superseded by the WEU by the Modified Treaty of Brussels	23 October 1954
Preceded by Succeeded by Treaty of Dunkirk Western European Union
Today part of	EU (CSDP) NATO Council of Europe

Part of a series on the
History of the European Union
Timeline Pre-1948 ideas 1948–1957 1958–1972 1973–1993 1993–2004 2004–present
Organisation European Communities (1958–2009) European Coal and Steel Community (1952–2002) European Economic Community (1958–1993) European Atomic Energy Community (1958–present) European Community (1993–2009) Justice and Home Affairs (1993–2003) Police and Judicial Co-operation in Criminal Matters (2003–2009) Common Foreign and Security Policy pillar (1993–2009) Western European Union (1954–2011) Western Union (1948–1954)
Treaties Treaty of Paris 1951 Treaty of Rome 1957 Merger Treaty 1965 Single European Act 1986 Maastricht Treaty 1992 Treaty of Amsterdam 1997 Treaty of Nice 2001 Treaty of Lisbon 2007
Commissions Hallstein Commission 1958 Rey Commission 1967 Malfatti Commission 1970 Mansholt Commission 1972 Ortoli Commission 1973 Jenkins Commission 1977 Thorn Commission 1981 Delors Commission 1985 Santer Commission 1994 Prodi Commission 1999 Barroso Commission 2004 Juncker Commission 2014 Von der Leyen Commission 2019
Topics History of Europe History of the euro History of defence integration History of enlargement List of presidents List of founders
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During the Korean War (1950–1953), the headquarters, personnel and plans of the WU's defence arm, the Western Union Defence Organisation (WUDO), were transferred to the newly established North Atlantic Treaty Organization (NATO), providing the nucleus of the European half of NATO's command structure (Allied Command Europe), led by Supreme Headquarters Allied Powers Europe (SHAPE). As a consequence of the failure of the European Defence Community in 1954, the London and Paris Conferences led to the Modified Treaty of Brussels (MTB) through which the Western Union was transformed into the Western European Union (WEU) and was joined by Italy and West Germany. As the WEU's functions were transferred to the European Union's (EU) European Security and Defence Policy (ESDP) at the turn of the 21st century, the Western Union is a precursor of both NATO and the military arm of the EU.