GhOST is an abbreviation of Global Operations, Surveillance and Tactics (the 'h' is added to create an interesting unit name), which is the operations arms of the GIA. GhOSTs are special paramilitary units of the Global Intelligence Agency (GIA) tasked with infiltrating behind enemy lines, striking at important command-and-control targets, gathering military intelligence, and providing surveillance. With the lose of air and space superiority to the Migou, and subsequent destruction of most of the NEG's space satellites, the importance of recon, surveillance and intel teams has grown tremendously. GhOSTs are secret units not officially acknowledged to exist by the government. Though paramilitary in nature they are answerable only to the President and specific intelligence oversight committees through the national security apparatus.
An ultra-secretive unit within GhOST called Blackspire is called in for the most sensitive missions, and is staffed by personnel whose identities have been completely erased.