BGen Watson graduated from Cornell University in 1991 with a BA in history, and was commissioned through the NROTC program. After The Basic School and Infantry Officer Course, he reported to 3rd Battalion, 8th Marine Regiment, in Camp Lejeune, NC, where he served as a Rifle Platoon Commander, Weapons Platoon Commander and Executive Officer with Company K, including deployments with the 24th and 26th MEU(SOC).

BGen Watson's other operational assignments include: Commanding Officer, Weapons Company, 2nd Battalion, 6th Marines, and Operations Officer, 2nd Battalion, 6th Marines, from 1999-2002, including deployments with the 22nd and 24th MEU(SOC), participating in Operations Provide Promise and Deny Flight in and around the former Yugoslavia, as well as Operation Dynamic Response in Kosovo; G-3 Future Operations Planner, I Marine Expeditionary Force (Forward), from 2006-2007 in support of Operation Iraqi Freedom, including service with Regimental Combat Team-7; G-3 Plans Officer, 1st Marine Division, from 2007-2008; Commanding Officer, 3rd Battalion, 1st Marines, from 2008-2011, including deployments as Battalion Landing Team 3/1 on a 31st MEU deployment, and to Helmand Province, Afghanistan, in support of Operation Enduring Freedom; Assistant Division Commander, 2nd Marine Division, from 2016-2017; and Commanding General (CG) of Task Force Southwest in Helmand Province, Afghanistan, from January to November 2018.

His service outside the operating forces includes duty as a tactics instructor at The Basic School from 1995-1997, and at the Infantry Officer Course from 1997-1998. From 2002-2005, he served as an instructor and faculty advisor at the Expeditionary Warfare School. From 2012-2013, he served in the Office of the Secretary of Defense as Senior Military Assistant to the Assistant Secretary of Defense for Asian & Pacific Security Affairs. From 2013-2014, he was assigned to the Office of Secretary of Defense Chuck Hagel for duty as Special Assistant to the Chief of Staff. BGen Watson served as the Commanding Officer of Marine Barracks, Washington D.C. (8th & I), from 2014-16. From 2018-2019, BGen Watson served as the CG of Marine Corps Installations East / Marine Corps Base Camp Lejeune, prior to assuming his current assignment as CG of the Marine Corps Warfighting Laboratory / Futures Directorate and Vice Chief of the Office of Naval Research.

BGen Watson is a graduate of the Marine Corps Summer Mountain Leaders Course, Amphibious Warfare School, Marine Corps Command & Staff College (Non-Resident), Marine Corps School of Advanced Warfighting, and the National War College.