A.D.P. Heeney was under-secretary of the department of external affairs from 1949-1952. When he became under-secretary, the department was under strain. It had grown rapidly in size and scope in the 1940s, but it did not function smoothly. Heeney excelled at administration. During his term, he established new divisions and sections, overhauled the administrative systems of the department, increased communication, and improved work conditions for employees. Heeney also had definite views about the substance of foreign policy and the conduct of Canadian diplomacy. He believed that trade was a vital component of foreign policy. And he believed that the best way to conduct relations with the US was through quiet diplomacy, an approach that fell out of favour as anti-American sentiment swelled in Canadain the 1960s. Although he had a long-term influence on the development of the department, he was more of a renovator than an architect.