[1] A career foreign service officer, Hill was a senior adviser to George Shultz, Henry Kissinger, and Ronald Reagan, as well as Boutros Boutros-Ghali, the sixth secretary-general of the United Nations.

[2] As part of the Foreign Service, Hill was posted to Switzerland, Taiwan, Hong Kong, and South Vietnam.

[2] Hill became political counselor for the U.S. Embassy in Tel Aviv in 1979, before being appointed director of Arab–Israeli affairs two years later and deputy assistant secretary of state for the Middle East in 1982.

During this time, Hill was involved in nuclear arms control negotiations with the Soviet Union, as well as reaching out to Yasser Arafat.

[2] He notably created the Brady–Johnson Program in Grand Strategy in 2000, together with Paul Kennedy and John Gaddis.

[2][5] The three of them taught a year-long course titled "Studies in Grand Strategy", which looked at wide-ranging issues in statecraft and social change, while employing classical writings of history and literature.

[2] He also taught for over two decades on the university's Program in Directed Studies, an interdisciplinary examination of texts from Western classical tradition.

[11] Hill worked as chief foreign policy advisor to Rudy Giuliani during his 2008 presidential campaign.