While the process of integrating the Allied fleets into the Interstellar Compact Navy was relatively straightforward, creating a unified ground combat force proved more difficult. With the demands of war against the Kyrans, and their mandatory service laws, the Free Worlds Republic had employed large ground forces with ample support from both crewed and autonomous heavy weapons, vehicles, and aircraft. The Terran Interstellar Union, on the other hand, had made use of smaller numbers of largely space-borne special operators with extensive drone support, colloquially referred to as "marines," preferring to rely on their fleet as the main line of defense.
The Compact Naval Infantry Corps—chartered by Executive Order in 2403—was one product of a compromise between these two doctrines. The original mission of the NIC was restricted to the defense of ICN facilities and ships, and the capture of enemy ships and installations. Over time, the mission of the initially tiny Corps would expand, and the organization would have to expand along with it. By the time the Great War began, the NIC had already adapted its doctrine and training to accommodate more localized ground operations, and the demands of war would only see that capability increase. By the end of the war, the NIC regular forces had ballooned into a massive military organization rivalling pre-war Planetary Defense Forces in size.
Today, under budget pressures, the NIC regular force has contracted almost to its pre-war size. RegForce marines—as they are still colloquially known—are once again largely restricted to the defense of navy ships and installations, and such places planetside that the navy is tasked with guarding. Now, it is the Naval Infantry Special Forces who draw the bulk of the Corp's funding, and engage in more direct operations against forces hostile to the Compact.
Whatever their mission, Naval Infantry are always expected to live up to the values in the Corps' motto: Valor, Strength, Honor.
As a sub-branch within the navy, the NIC makes use of a naval rank and command system at all levels. The Corps is commanded by Rear Admiral, who sits on the Interstellar General Staff (IGS). The Corps is then divided up into a number of divisions, each commanded by a Commodore. In the latter half of the Great War, these divisions were sometimes deployed intact as combat forces; however, in ordinary circumstances, NIC divisions serve only as organizational units.
The largest units which may (rarely) be deployed intact are brigades, commanded by Brigade Captains (Brigadiers), though more commonly battalions, commanded by Captains or Commanders, are the standard deployment unit.
In practice, the primary combat unit of the NIC is either the platoon or the squad, commanded by Junior Lieutenants or Warrant and Petty Officers. These small units offer the flexibility demanded of most NIC missions, while still employing substantial firepower through the use of autonomous weapon platforms.
Due to their specialized training and mission, and their small size, the Naval Infantry were originally considered a special forces unit. As the Corps' mission increased, however, so too did the need for a dedicated special action group within the organization, an elite unit which could carry out missions for which even the Corps was too cumbersome, or visible.
The Long Distance Reconnaissance Group (LDRG) was born of that need shortly before the Great War. Originally tasked with infiltrating then-recently discovered Cipher occupied planets near Pyria and the UCC, when the war began the LDRG's mission expanded with the rest of the Corps. That expanded mission survived the war, as the need for clandestine operations only grew with the official end of hostilities.
Today, the LDRG still operates almost exclusively in enemy held or neutral territory. In addition to gathering vital intelligence, they are often tasked with surgical elimination of key targets and enemy assets. Given that they remain Naval Infantry, their mission targets are usually either in space, or are ones in which strong coordination with naval elements is required for success.
While technically a force within the navy, like the other Compact special forces the LDRG falls under the purview of Interstellar Special Operations Command (ISOC), the umbrella special forces organization founded in 2482 to help coordinate clandestine and special action efforts in the final years of the war.
