After completion of the Infantry Officers Basic, Ranger, and Airborne Courses, and an initial assignment at Fort Hood, Texas, Hill served with the 2–502nd Infantry, part of the 101st Airborne Division (Airmobile), in the Republic of Vietnam as a rifle platoon leader, recon platoon leader, company executive officer, and company commander.

General Hill then served as the Assistant Deputy Director for Politico-Military Affairs on the Joint Staff from October 1992 to July 1994.

In that role he was responsible for requesting maximally permissive "enhanced interrogation" policies that led to torture in the Guantanamo Bay detention camp.

[4] In addition, he an advisor to and on the board of The Protective Group, a Texas-based security firm, and a consultant to Northrop Grumman and the Center for Molecular Biology and Enterprise Technology Partners.

In Coral Gables he serves on the city's Emergency Management Committee, and he is a national advisor to The Military Child Education Coalition.