for which the British Methodist Robert Newton Flew edited an influential volume of studies, The Nature of the Church. Subsequent mergers were with the International Missionary Council in 1961 and the World Council of Christian Education, with its roots in the 18th century Sunday School movement, in 1971. WCC member churches include the Assyrian Church of the East and the Oriental Orthodox Churches, almost all of the Eastern Orthodox Churches and Lutheran Churches; the Moravian Church; the Anglican Communion; some Old Catholic Churches; the Methodist churches; the Presbyterian and other Reformed churches, a sampling of united and independent churches, and some Baptist and Pentecostal churches. Many churches who refused to join the WCC joined to form the World Evangelical Alliance. Delegates sent from the member churches meet every seven or eight years in an Assembly, which elects a Central Committee that governs between Assemblies. A variety of other committees and commissions answer to the Central Committee and its staff. Assemblies have been held since 1948. The "human rights abuses in communist countries evoked grave concern among the leaders of the World Council of Churches." However, historian Christopher Andrew claims that, during the Cold War, a number of important WCC representatives of the Orthodox Church in Eastern Europe had been working for the KGB, and that they influenced the policy of the WCC. From 1955 to 1958, Robert S. Bilheimer co-chaired a WCC international commission to prepare a document addressing the threat of nuclear warfare during the Cold War. At the 1961 conference, a 32-year-old Russian Orthodox Bishop named Aleksey Ridiger was sent as delegate to the assembly, and then appointed to the WCC's central committee. He was later elected as Russian patriarch in 1990 as Alexei II. The ninth assembly took place in Porto Alegre, Brazil in February 2006, under the theme "God, in your grace, transform the world". During the first Assemblies, theologians Vasileios Ioannidis and Amilkas Alivizatos contributed significantly to the debates that led to the drafting of the "Toronto Statement", a foundational document which facilitated Eastern Orthodox participation in the organization and today it constitutes its ecclesiological charter. The 10th Assembly was held in Busan, Republic of Korea, from 30 October to 8 November 2013. In 2013 Dr. Agnes Abuom of Nairobi, from the Anglican Church of Kenya, was elected as moderator of the Central Committee of the World Council of Churches; she is the first woman