ISOC and TJOC have their origins in Humanities first major colonization attempts in the 2100s. Originally Union forces were organized under a single command that organized military forces from the numerous nations under the American Union. Managing the host nation's own military forces and politics along with those of the early colonies and doing so with the rather massive communications delay made operations within the solar system difficult, and interstellar operations nearly impossible.

The ISOC would be formed in 2180 to help resolve this issue. the ISOC consolidated the American Union's colonization efforts under one organization. This would start with creating command and control infrastructure for various colonial assets, and expand to include joint training and procurement for forces by 2240. By 2250 the incident surrounding Yelton Veda would convince ISOC that it needed to have its own forces, and would lead to the creation of Marine and Naval groups that reported directly to ISOC instead of the local colonial authorities.

By 2300, ISOC manages all major military efforts for the union starting from Luna and extending outward to the furthermost colonies. Incidents at the 2319 International Summit would lead to the American Union forcibly disbanding star-ships contributed to ISOC by the Magnetic Assembly in retaliation for going against the party-line by standing against DaQin forces in the frontier. This would cripple ISOC's interstellar logistics operations, and leave them poorly positioned to deal with the New Years Revolution in 2320 in the Hawking System where the American Union military suffered its greatest defeat since its founding when their assets in the Hawking system were either arrested or sized. The lack of support assets also directly contributed to their loss at the Battle of Riess less than a month later when assets from Atlantica were pulled in to try and retake a foothold in the Hawking System.

ISOC accepts forces in from various organizations associated with the American Union including Colonial security forces and terrestrial nation military forces. These recruits are then processed through ISOC's own military command structure to form new units directly under ISOC's command.

ISOC itself, and the headquarters group responsible for co-ordination between local security forces and the Union military as well as the logistical needs of the entire organization. ISOC command is based on Mars.

Originally put together for the defense of the Atlantica system, the 6th fleet is a relatively small force that had shrunk down to only 6 Statesmen class warships in 2320, and was tasked with retaking Reiss from forces Loyal to the Magnetic Assembly during the battle of Reiss. The ill-fated battle and follow up strike on Ur would see the 6th fleet destroyed.

Formed in 2320 shortly after the New Years Revolution on Hawking. The 26th fleet was tasked with retaking the Hawking System. Due to the time constraints involved, the 26th fleet would be fed by Assets taken from other fleets throughout Union Space.

Formed in 2318, though existing in only a managerial aspect until ships were finally assigned in 2320, the 45th fleet exists to oversee exploration of the Outremer system.

The 54th fleet is tasked with defense of the Shen Zhou SLE as part of Operation Distant Flock.