The Western European Union ( WEU ) is a European defense and security organization . It was set up by Treaty of Brussels of 1948 , West Germany and Italy joined in 1954 . The Western European Union ( WEU ; French : Union de l'Europe occidentale , UEO ) will be until June 2011 an international organization tasked with implementing the Modified Treaty of Brussels ( 1954 ) , an amended version of the original 1948 Treaty of Brussels .