(b. Heerenveen, 17 Nov. 1894; d. Almoçagême, Portugal, 17 June 1983)
Netherlandish; Minister of Foreign Affairs After law study at Leiden, which he completed in 1918 with a dissertation on the relations between the Netherlands and Japan since 1605, Van Kleffens worked for a time in the secretariat of the League of Nations and then with the Shell group in London (1920–2). From 1922 until 1958 he served in the Ministry of Foreign Affairs, and from 1929 as head of the Division of Diplomatic Affairs. On the point of leaving the Netherlands as head of the Dutch Legation in Bern, he was asked to accept the portfolio of Foreign Affairs in the new De Geer Cabinet, which was to become the government in exile in 1940. During the war period he shared in international preparations for the establishment of the United Nations, generally acting as champion of the rights of smaller states over the great powers. He developed ideas about regional co-operation and security arrangements which foreshadowed the later establishment of NATO. He exchanged the Ministry for Foreign Affairs in the first post-war Cabinet for the post of Minister without Portfolio (1946) and Permanent Representative of the Netherlands at the Security Council (1946–7). The next three years he was Dutch ambassador in Washington. In 1950 he requested a quieter post, becoming ambassador in Portugal (1950–6). In 1954 he presided over the Ninth Session of the General Assembly of the United Nations. In 1956 he became Permanent Representative for the Dutch government to NATO and the OEEC at Paris. For the last nine years of his public career he was Representative of the High Authority of the European Coal and Steel Community in the UK. He returned to Portugal on retirement.