The Marine Corps hadn’t had a Special Operations unit since World War II, but all of that changed in 2003 when on June of that year, the Marine Corps and USSOCOM formed Marine Corps Special Operations Command Detachment One (MCSOCOM Det 1) to explore unit level Marine Corps participation in USSOCOM. Prior to this, Marine Corps brass were vocal against an “elite within an elite” as they considered all Marine Corps units elite.

MCSOCOM Det One deployed with a Naval Special Warfare unit in support of Operation Iraqi Freedom in 2004.

After the deployment, the Marine Corps contributions were studied, and in October 2005, the Secretary of Defense directed the formation of a Marine component of U.S. Special Operations Command. It was determined the Marine Corps would initially form a unit of approximately 2,500 to serve within the Special Operations Forces (SOF) community.

On Feb. 24, 2006, MARSOC was activated at Camp Lejeune, N.C. MARSOC initially consisted of a small headquarters staff and a battalion level unit which had been formed to train, advise, and assist partner nation militaries by conducting the mission of Foreign Internal Defense.