MCSOCOM Detachment One Marine Corps Special Operations Command Detachment One ( MCSOCOM Detachment One or Det 1 ) , was a pilot program to assess the value of Marine special operations forces permanently detached to the United States Special Operations Command . It was commanded by Col . Robert J . Coates , former commanding officer of 1st Force Reconnaissance Company . Det One was activated on June 19 , 2003 and had its headquarters at Camp Del Mar Boat Basin . It was disbanded in 2006 and succeeded by the permanent United States Marine Corps Forces Special Operations Command , which is to be a 2700 - person command . Personnel . The unit consisted of 81 Marines and 5 Navy Corpsmen divided among 4 sections : The original Marines picked to form the detachment were hand - picked from over 500 personnel records . Despite common misconception , Det One was not a beefed up Force Reconnaissance platoon . While the reconnaissance element was composed mostly of Force Recon Marines , they made up only 24 of the 86 members of the detachment . The detachment , though lacking organic aviation , operated under the Marine Air - Ground Task Force philosophy of leveraging integrated , complementary capabilities to be more effective than the sum of its parts . Insignia . Detachment One ' s Insignia comes from the World War II Marine Raider ' s patch , a blue patch with a skull and stars . The insignia was created by then - GySgt Anthony Siciliano . The scarlet , blue , and gold disk represents the unit ' s joint Navy - Marine Corps origins . The crossed stiletto / lightning bolt represent the unit ' s special operations mission , and its global communications reach . The parachute wings represent airborne - qualified status and the mask above it represents the combatant diver qualification . History . Although Detachment One was a relatively new unit its heritage can be traced back to the World War II Marine Raiders . In World War II , the Marine Raiders were formed to seize key beaches and hills and also conduct guerrilla - style strikes against Imperial Japanese Forces . After two years the Raiders were disbanded but they set the stage for other raider - style units like Detachment One . In 1986 , when the Department of Defense established the new joint Special Operations Command , the Marine Corps opted not to participate . Then Commandant Paul X . Kelley expressed the belief popular in the Corps that Marines should support Marines , and that the Corps should not fund a special warfare capability that would operate independently of the Fleet Marine Force . The Corps wanted to retain the Corps ' Force Reconnaissance units within the MAGTF command structure and prevent the development of an " elite " within the Marine Corps . Marine Corps leadership believed that such a development would be at the expense of the effectiveness of the Corps as a whole . However , following the September 11 attacks and the current global war on terror , that view began to shift . Defense Secretary Rumsfeld immediately directed the Marine Corps and USSOCOM to work more closely together in what would be called the global war on terror . Marine resistance to special warfare units dissipated when Marine leaders watched the Corps ' " crown jewels " – the 15th and 26th MEU Maritime Special Purpose Force s – sit on the sidelines during the early stages of Operation Enduring Freedom while other special warfare units led the way . Resistance from SOF commanders already in - country and indifference from the Navy chain of command left the MEU ( SOC ) s unused for over a month , relegated to supporting roles where SOF lacked manpower . In October 2002 , Commandant James L . Jones , after consultation with USSOCOM leaders , directed the establishment of a Marine unit for permanent USSOCOM employment . Out of this came the T / O for Detachment One , officially activated aboard Camp Pendleton on June 19 , 2003 . After completion of Navy special warfare ( NSW ) certification and other training , Det One was deployed to Iraq in March 2004 for Operation Iraqi Freedom . Operating under Naval Special Warfare Group One , Det One executed direct action , coalition support , and battlefield - shaping operations . A study conducted by the Joint Special Operations University ( JSOU ) found that The trial deployment demonstrated the MCSOCOM Det could effectively conduct direct action ( DA ) and special reconnaissance ( SR ) . It is reasonable to suggest that the Detachment could also conduct or support foreign internal defense ( FID ) , counter - terrorism ( CT ) , special activities , selected theater security cooperation plans ( TSCP ) , and other tasks as required . However , the deployment also revealed interservice tensions . The Navy commander of Naval Special Warfare Squadron One did not utilize Det One as a cohesive unit , but parceled its capabilities as needed . In particular , the intelligence section was parceled out to other Navy units , instead of supporting Det One operations , as the Navy lacked intelligence personnel who understood ground combat . Following the conclusion of the deployment in September 2004 , the Marine Corps and USSOCOM continued to negotiate details of the long - term relationship through 2005 , while Det One trained for a possible second deployment . Though deployment proposals were rejected on the basis that Det One was to provide the nucleus of the future permanent MARSOC organization , it was disbanded on March 10 , 2006 and its members dispersed throughout the Marine Corps . The experience of Det One provided critical intelligence on the organization and integration of a Marine special - operations force into USSOCOM and was instrumental to the planning of MARSOC .