Henry G. Chiles Jr. entered from the United States Naval Academy as a midshipman in 1956, graduating in 1960 with a Bachelor of Science degree.

Lt. Chiles' next assignment was as an engineering officer with the Blue crew of the nuclear-powered ballistic missile submarine USS Tecumseh from January 1966 to February 1968.

The submarine also conducted a refueling overhaul in record time and a Western Pacific deployment before Chiles departed on 15 October 1979.

Chiles served as director, Strategic Submarine Division and Deputy Assistant Chief of Naval Operations for undersea warfare between July 1985 and September 1987 and was promoted to rear admiral (lower half).

On 24 September 1993, Vice Admiral Chiles became the deputy commander-in-chief and chief of staff for the United States Strategic Command (STRATCOM) at Offutt Air Force Base.

[3][4] The primary focus of Chiles' tenure as USCINCSTRAT was adjusting the structure and mission for U.S. strategic nuclear forces in a post-Cold War environment.

He is also a recipient of the Distinguished Graduate Award (DGA) of the Naval Academy Alumni Association in 2008[7] Admiral Chiles serves as an adjunct fellow with the Center for Strategic and International Studies (CSIS).