Major General Nash is the son of a career U.S. Naval Officer. After graduating from Hampden-Sydney College, he completed Officer Candidates School and received his commission in December 1971. Major General Nash's assignments have included tours with Marine Corps Operating Forces in the 1st, 2nd and 3rd Marine Divisions, and with I, II and III Marine Expeditionary Forces. He has commanded Marine Corps operating forces from the platoon to the division level, and served at different times as executive officer, operations officer, and logistics officer in a variety of units. In August 1986, Major General Nash was selected to reactivate and command the 1st Force Reconnaissance Company. He has served as the Commanding General, 3rd Force Service Support Group and the 3rd Marine Division, both headquartered in Okinawa, Japan.

Major General Nash has served tours outside Marine Corps operating forces at the Officer Candidates School, Officer Assignment Branch, Headquarters Marine Corps, with the Plans Division, Plans, Policy and Operations, Headquarters Marine Corps, with Observer Group Lebanon with the UN Truce Supervision Organization-Palestine, with the Special Forces Schools, Fort Bragg, NC and with the Joint Special Operations Command (JSOC), Fort Bragg, NC. During the assignment with JSOC, he also served as the J-3 for Task Force Ranger in Somalia. In the spring of 1998, he commanded Joint Task Force Auburn Endeavor in support of Department of Energy efforts in Tbilisi, Georgia. He has served as the Director Operations Division, Plans, Policies and Operations, Headquarters Marine Corps. Prior to his current assignment, he served as Commander, Joint Warfighting Center and Director, Joint Training J7, United States Joint Forces Command, Suffolk, Virginia.

His professional military education has included attendance at the Amphibious Warfare School, the United States Army Special Forces Qualification Course, the Marine Corps Command and Staff College, and the National War College.

Major General Nash's personal awards include the Defense Superior Service Medal with Oak Leaf Cluster, the Legion of Merit with Gold Star, the Defense Meritorious Service Medal with Oak Leaf Cluster, the Meritorious Service Medal with Gold Star, the Army Commendation Medal with Oak Leaf Cluster, the Army Achievement Medal with Oak Leaf Cluster, the Navy and Marine Corps Achievement Medal, the Combat Action Ribbon, the Army Special Forces Tab, the Army Master Parachutist Insignia, the British Army Parachutist Insignia, and the Royal Thai Marine Corps Parachutist Insignia.