 In 1969, Diggs was appointed to the post of Chairman of the Subcommittee on Africa of the Committee on Foreign Affairs, where he strongly advocated ending Apartheid in South Africa.He was a committed publicist for the liberation cause in South Africa, and his 'Action Manifesto' (1972) displayed his support for the armed struggle against Apartheid.In it, Diggs criticized the United States government for decrying the use of such violence when it failed to condemn measures used by the South African government to subjugate the majority of its own people.