Sergeant Major Robertson reported to MCRD Parris Island in June 1996 and completed recruit training. After graduation from Recruit Training in September 1996, Private First Class Robertson reported to The School of Infantry, Camp Geiger, North Carolina and was assigned the 0352 Antitank Assault Guided Missile man MOS.
In December of 1996, Private First Class Robertson reported to 8th Marine Regiment, Camp Lejeune, North Carolina. While assigned to 8th Marine Regiment, he participated in Combined Arms Exercise at the Marine Corps Air Ground Combat Center in 29 Palms California, participated in Type Commanders Amphibious Training exercise, and completed cold weather training at the Marine Corps Mountain Warfare Training Center in Bridgeport California. In April of 1998, Corporal Robertson was assigned to Weapons Company, 3d Battalion, 8th Marines Combined Anti-Armor Platoon. During this tour, Corporal Robertson deployed as a member of the Battalion Landing Team assigned to the 26th Marine Expeditionary Unit. He participated in operations Allied Force, Joint Guardian, Shining Hope, and Avid Response. Corporal Robertson served in a number of billets and was a member of the Battalion Fire Support Team.
In October of 2000, Sergeant Robertson reported to 2d Battalion, 23d Marines, Company E, Inspector Instructor Staff, San Bruno California for duty. Shortly after his arrival, Sergeant Robertson, serving in an integrated billet, was transferred to Camp Pendleton in support of Operation Enduring Freedom (OEF). The Battalion was attached to First Marine Expeditionary Force as part of Regimental Combat Team I and deployed to Iraq in support of Operation Iraqi Freedom. Sgt Robertson served as the A-T MAN and held the billets of Company Police Sergeant, Rifle Platoon Squad Leader, Armory NCOIC, Communications NCOIC, and Motor T NCOIC.
In November 2003, Staff Sergeant Robertson received orders to 3d Battalion, 2d Marines. During this tour, Staff Sergeant Robertson deployed to U.S. Naval Base Guantanamo Bay, Cuba in support of OEF and to Iraq in support of OIF. Staff Sergeant Robertson served in the billets of Rifle Platoon Sergeant, Mobile Assault Platoon Sergeant/Commander, Company Gunnery Sergeant, and Company First Sergeant.
In July of 2006 Gunnery Sergeant Robertson executed orders to Drill Instructor School, MCRD San Diego. Upon completion of DI School, he was assigned to 2d Recruit Training Battalion Company E. During this tour, he completed ten training cycles with Company E and G serving as a Green Belt Drill Instructor, Senior Drill Instructor, and Chief Drill Instructor.
In August of 2009, Gunnery Sergeant Robertson received orders and reported to 1st Battalion, 8th Marines. He was selected to the rank of First Sergeant and assigned as the Company First Sergeant, Company A where he deployed to Afghanistan in support of OEF. Upon return from deployment 1stSgt Robertson was re-assigned to Weapons Company where he completed another tour in Afghanistan.
In October 2012, First Sergeant Robertson received orders to MARSOC and was assigned as the Company 1stSgt, Headquarters Company, 3d Marine Raider Support Battalion.
In October of 2015, Sergeant Major Robertson received orders to Marine Heavy Helicopter Training Squadron 302 where he posted as the Squadron Sergeant Major.