Colonel Clingan enlisted in the Marine Corps Reserve in 1989 and deployed to Operations DESERT SHIELD/STORM in 1990-1991 with the 4th Civil Affairs Group. He was commissioned in 1993 through the Naval Reserve Officer Training Corps program after graduating from the American University with a degree in International Studies.
As a company grade officer, his operational assignments were Rifle Platoon Commander and Company Executive Officer, 2d Battalion, 1st Marines; and Weapons and Rifle Company Commander, 3d Battalion, 3d Marines (Operation ENDURING FREEDOM – PHILIPPINES 2003).
As a field grade officer, his operational assignments were Operations and Executive Officer, Headquarters Battalion, 2d Marine Division; Operations and Executive Officer, 3d Battalion, 6th Marines (Operation IRAQI FREEDOM 2007 & 2008); Current Operations Officer, G-3, 1st Marine Division (Forward) (Operation ENDURING FREEDOM 2010-11); Battalion Commander, 3d Light Armored Reconnaissance Battalion (Operation ENDURING FREEDOM 2012); and G-35, Future Operations Officer, Marine Forces Europe and Africa.
His supporting establishment assignments include service as an instructor at The Basic School (TBS) 1997-2000, again as the Director of the Warfighting Instructor Group 2009-2010, and as the Commanding Officer 2016-2018.
His joint duty assignment was as the Operations Officer, United Nations Command Military Armistice Commission, Republic of Korea, 2003-2005.
His professional military education includes: TBS Basic Officer Course (General’s Honor Roll) and Infantry Officers Course; Amphibious Warfare School (Distinguished Graduate); Weapons and Tactics Instructor (WTI) course; Marine Corps Command and Staff College (Distinguished Graduate with Masters of Military Studies); Naval War College, (President’s Honor Graduate/Highest Distinction with Masters of Strategic Studies).