東南アジア条約機構
He returned to the public service and was appointed official secretary to the Australian High Commission in Ottawa, Ontario, Canada. He then spent a year at the Royal College of Defence Studies in Britain. He was appointed Australian Ambassador to Thailand, and played an important role in the early days of the Southeast Asia Treaty Organization (SEATO). In 1961 he returned to Canada as High Commissioner, from where he was appointed Ambassador to the United Nations 1964–65.