Throughout its history, Vietnam's main foreign relationship has been with various Chinese dynasties. Following the partition of Vietnam in 1954, North Vietnam maintained relations with the Eastern Bloc, South Vietnam maintained relations with the Western Bloc. Despite these differences, Vietnam's sovereign principles and insistence on cultural independence have been laid down in numerous documents over the centuries before its independence. These include the 11th-century patriotic poem "''Nam quốc sơn hà''" and the 1428 proclamation of independence "''Bình Ngô đại cáo''". Though China and Vietnam are now formally at peace, significant territorial tensions remain between the two countries over the South China Sea. Vietnam holds membership in 63 international organisations, including the United Nations (UN), Association of Southeast Asian Nations (ASEAN), Non-Aligned Movement (NAM), International Organisation of the Francophonie (La Francophonie), and World Trade Organization (WTO). It also maintains relations with over 650 non-governmental organisations. As of 2010 Vietnam had established diplomatic relations with 178 countries.