The 1st Special Forces Operational Detachment-Delta (SFOD-D) is one of two units in the United States Armed Forces assigned primarily to combat terrorism. The other is the Navy's 'Dev Group.' Delta members are experts at counterinsurgency, small unit tactics, and various infiltration techniques.

Many of them come from Ranger battalions or Special Forces (Green Berets) groups. They are well seasoned, well conditioned and are some of the most experienced soldiers in the service. But as Mark Bowden, author of Black Hawk Down, said, "They are professional soldiers who hate the army." They are very independent warriors who like working in small teams and are very resilient.

While the military acknowledges the existence of special mission units like Delta Force, it does not specify what they are called or their locations, staffing or organizational structure. Unofficially, Delta Force is considered one of the U.S. military's elite special operations units, its members drawn from all branches. Based at Fort Bragg, North Carolina, its formal name is 1st Special Forces Operational Detachment - Delta.

Delta Force was created by Army Col. Charles Beckwith in the late 1970s and based on the British Special Air Service counter terrorism unit. Its members are known as "operators" and divided into three squadrons. Details of the composition, strength, abilities and operations of Delta Force remain a closely guarded secret. But the unit is thought to be equipped with the most advanced weaponry and equipment the U.S. military has to offer. Unit members undergo an extensive selection and assessment process before joining the unit.

Hostage rescue is considered a Delta Force specialty. In 1989, during Operation Just Cause in Panama, Delta Force operatives rescued U.S. businessman Kurt Muse from Modelo Prison in Panama City. Muse had been arrested for running a CIA-supplied clandestine radio station.

Delta Force members are selected for specific traits, whether it's language skills, an ability to shoot someone from a half-mile away or extreme physical endurance. But usually they pick them for a lack of showy machismo. They're extremely low-key; some of them look like superheroes, but most of them tend to be laid-back, slow to anger, not show-offy in any way. For one thing, it's difficult to be the best in an occupation and yet be sworn to secrecy. Once you're in that unit you dress as a civilian, wear civilian hair and can grow a beard.

They live in a private secret world and don't tell anyone what they do. They train constantly. They're ascetics because part of the discipline is being able to dig a hole and live in it for a week or get dropped in the middle of a desert and find your way out.

They like to say that Delta Force is the haven for great soldiers who hate the army. They're older than most soldiers, they like what they do and hate the chain of command. They call each other by nicknames and don't really recognize rank. Some of the most respected people in those units are noncommissioned officers, sergeants.