Delta Force

This super-secretive US Army outfit goes by several names

Delta Force
1st Special Forces Operational Detachment-Delta (1st SFOD-D)
Combat Applications Group (CAG)
Delta

Delta Force - Role

Delta's main mission is counter-terrorism. This includes:

hostage rescue
elimination of terrorist forces
intelligence gathering on terrorist threats

Other roles include:

assassination / arrest of enemy leadership
unconventional warfare

Delta Force - Organization

Delta Force's structure is similar to the British 22nd Special Air Service Regiment, the unit which inspired Delta's creator, Charles Beckworth. Delta is organized into Squadrons of around 70 men. Each squadron is made up of 16-man troops. Each troop specializes in a mode of insertion such as by Air (HALO, HAHO parachuting), Water (SCUBA, boats etc), Land (Vehicles) and Mountain (climbing and high-altitude specialists). Delta operators within each troop will often deploy in smaller 4-5 man teams.

Delta Force - Notable Operations

Since their inception, Delta Force have been involved in a series of operations.