Lieutenant General Smith was commissioned through the NROTC program at the University of North Carolina at Chapel Hill in May 1985.

A career infantry officer, his assignments in the operating forces include Rifle Platoon Commander and 81mm Mortar Platoon Commander in 2d Battalion, 1st Marines; Logistics Officer and Rifle Company Commander in 1st Battalion, 3d Marines; and Commanding Officer, 1st Force Reconnaissance Company, during which he deployed twice in support of Operation IRAQI FREEDOM.

Other assignments include Series and Company Commander, MCRD, San Diego and Aide-de-Camp to the Commanding General; Inspector-Instructor, 4th Force Reconnaissance Company; Future Operations Planner, I Marine   Expeditionary Force G-3 and G-5; and Deputy Operations Officer, 1st Marine Division. He also served consecutively as Military Assistant to the Assistant Commandant and Military Secretary to the 35th Commandant of the Marine Corps.

From 2007 to 2010, Lieutenant General Smith served as the Commanding Officer, The Basic School in Quantico, Virginia.

As a General Officer, he served as Commanding General, MAGTF Training Command/Marine Corps Air Ground Combat Center, Twentynine Palms, California; Deputy Commander, Regional Command Southwest in Helmand Province, Afghanistan; Deputy Commanding General, Marine Corps Combat Development Command, Quantico, Virginia; Director, Manpower Plans and Policy Division, Quantico, Virginia; Director, Strategy, Plans and Policy Directorate, U.S. Central Command, MacDill AFB, Florida; Senior Military Assistant to the Secretary of Defense; and most recently as the Deputy Commandant for Plans, Policies, and Operations Headquarters, Marine Corps.

Lieutenant General Smith graduated with honors from: The Basic School, the U.S. Army Infantry Officers Advanced Course where he was the Distinguished Honor Graduate for Class 2-92, Marine Corps Command and Staff College, the School of Advanced Warfighting where he was the recipient of the General Clifton B. Cates Award, and the Marine Corps War College. He is also a graduate of the Joint Forces Staff College and the Advanced Management Program at Harvard Business School.

He has been privileged to serve in commands that have been awarded the Presidential Unit Citation, Joint Meritorious Unit Award, Navy Unit Commendation, and the Meritorious Unit Commendation.