 Around 1961, Harrop left Personnel and moved to the regional affairs office of the Bureau of European Affairs, where he replaced Arthur A. Hartman as a desk officer focused on EURATOM.In early 1962, Harrop was transferred (at Sheldon B. Vance's request) to the Bureau of African Affairs, where he was responsible for economic matters in the Congo (then in the midst of the Cold War-era Congo Crisis) and the Katanga secession.In 1963, Harrop went to Brussels to become a mid-grade economic officer and deputy to the Economic 
Counselor there.