At a time when the United States government had already listed Nelson Mandela as a terrorist, Wachuku, who was "widely respected" as Foreign Affairs Minister of Nigeria intervened with the South African government and helped save Nelson Mandela and others from the death penalty at the 1963–64 Rivonia Trial. In his 1962 diary, from Lagos: Nigeria, Nelson Mandela wrote: "Friday 18 May 1962: 1pm: OR and I meet Mr. Jaja Wachuku and his staff and have a profitable discussion. Saturday 19 May 1962: We have lunch with Jaja Wachuku."