With the chartering of the Interstellar Compact Navy (ICN) in 2400, the Naval Infantry Corps (NIC) in 2403, and the formation of the more heterogeneous Planetary Defense Forces (PDF) over the remainder of that decade, the Interstellar General Staff (IGS) believed they had accounted for all the combat situations the Compact was likely to find itself in. Their hope was that the navy would be able to deal with most threats before ground combat became necessary; that failing that, the PDF would be able to protect Compact planets from invasion, and the Naval Infantry would be able to tackle whatever remained thereafter. The chiefs did not at that time foresee the need to conduct large scale ground offensives against enemy-held planets.
The galaxy rapidly disabused them of that notion. Increasing Kyran raids against Free Worlds frontier systems, despite the formation of the Compact and the might of its navy, began to show the gaps in Compact capabilities. In particular, the "raid" against Anderson in 2446, which saw a Kyran force seize control of most of the small colony—and which took the undermanned NIC two weeks to dislodge—forced an emergency reassessment of the strategic situation. That same year, Executor Antony-3 ordered the formation of a new branch of the military whose sole mission would be conducting the kinds of orbital assaults that the IGS had once believed obsolete.
The Planetary Assault Corps was chartered in January of the following year, 2447. The youngest of the main branches of the ICDF, it in fact traces its lineage back the furthest. In TSY 1942, during Earth's Second World War, the Allies created a unique multinational special forces group called the 1st Special Service Force. In 2060, during the Third World War, a later Alliance reactivated this force, and it conducted the first-ever suborbital combat drop on the enemy's capital city, a daring operation that helped end the war. It is to this ancient force that the PAC traces its history, and from which it draws its motto: From On High, Victory.
The PAC played a vital role in the Great War, providing the spear-tip for every major planetary invasion and campaign of liberation conducted in that galaxy-spanning conflict. Even so, the PAC suffered the most drastic cuts during the drawdowns after the war, since its increasingly large regular forces were no longer deemed necessary. Still, its special forces continue their important missions in support of Compact interests, and a core of experienced regular forces remains, waiting for the day when they will once again be called upon to fall from the skies upon the Compact's enemies.
The PAC is structured much like the Free Worlds Army, and the armies of old Earth from which that force drew inspiration. It is commanded by a Marshal with a seat on the IGS; it is then split into divisions commanded by a Lieutenant or Major General. Each division is split into brigades, commanded usually by a Brigadier, which are the primary tactical deployment unit.
The PAC is the nominal parent organization for two special forces units.
The larger of these is the Special Warfare Brigade. Formed in 2479, during the Great War, the SWB was tasked with operating on Compact planets which had been conquered and occupied by the Kyrans and the Ciphers. Special Warfare operators would infiltrate onto these planets via stealth drop, then link up with local resistance movements or regular military forces which had become cut off, training and equipping them to conduct sabotage operations against enemy forces. Once regular PAC and other Compact forces arrived to liberate the planet, SWB operators would assist these campaigns by intensifying sabotage and direct attack operations behind enemy lines.
Today, the SWB is primarily tasked with aiding local security forces on allied and Protectorate worlds such as Pyria, Ranak, and Byas as they deal with insurgencies which are themselves funded and equipped by hostile third parties.
The other PAC special force, the Clandestine Reconnaissance and Tactics Group, actually predates the PAC itself. The CRTG was black ops force created by the Free Worlds Coalition during the Third Kyran War (2356 - 2365). It mission was to operate primarily in enemy territory, causing mayhem far behind the lines on alien worlds the Kyrans had occupied for centuries. In that conflict, as well as later, the unit's ruthless tactics came under intense criticism from the TIU and the UCC, with a large number of noncombatant deaths on Kyran being attributed to them.
Nevertheless, the CRTG saw action again during the Second Cipher War (2374 - 2379), and fell under the remit of the PAC shortly after the PAC was chartered in 2447, and conducted extensive operations under that banner during the Great War. The CRTG still operates almost entirely in the black to this day, with their proponents arguing that they are a vital clandestine tool for keeping the Compact's enemies off balance, and their critics laying all manner of assassinations and war crimes at their feet.
Like the Naval Infantry's Long Distance Reconnaissance Group, both the SWB and the CRTG have been under the remit of Interstellar Special Operations Command (ISOC) since the formation of that organization in 2480.
