United Nations Space Command

Background
The United Nations Space Command was formed by the United Nations during the Interplanetary War of the early twenty second century. After the UNSC victory, overpopulation on Earth became a major issue in the early 22nd century. This issue was resolved by colonizing and constructing vast cities on other planets in the Orion Arm of the galaxy, the Inner Colonies and later the Outer Colonies.

The UNSC's defensive military force is the UNSC Defense Force (UNSCDF), and consists of the UNSC Air Force, the UNSC Army,the UNSC Marine Corps and the UNSC Navy.

History
The UNSC has its roots in World War I, which led to the creation of the League of Nations. The League of Nations led to the formation of the United Nations after World War II. The UNSC was actually formed and fashioned as the result of a series of brutal conflicts across the Solar System and Humanity's space confines between 2160 and 2164, most prominently among them the Jovian Moons Campaign, The Rain Forest Wars, and a series of battles on Mars.The United Nations Space Command, as organized and orchestrated as it seems, is actually an emergency military government formed in such strife. These encounters were centered around U.N. clashes with dissident political movements, the most important of which were the "Koslovics" and the "Frieden". More specifically, the Frieden movement was a fascist organization based on the Jovian Moons, though they received backing from some corporations operating in the United German Republi on Earth, while their ideological opponents, the Koslovic, formed a group centered around the leadership of Vladimir Koslov

Interplanetary War
The war began with an attack on U.N. Colonial Advisers on the moon of Io, one of the moons of Jupiter, but would spread to Mars and parts of South America in the Rain Forest Wars. These events culminated in a U.N. build-up in the 2160s, which would result in the second of the great reforms, the first being from the League of Nations into the U.N. The second reformed the U.N. from a largely diplomatic organization to a permanent Unified Earth Government as an ultimate power to lead the human race by 2170.

Colonization
The four year long war put the spotlight on problems facing the overpopulated planet, and the Rain Forest Wars also exacerbated the problems relating to food distribution. The ensuing famine and societal problems related to the post-war population boom providing the spark to change the political nature of governance on Earth and elsewhere, leading to the political system seen in the 26th Century.

These pressures also helped make space colonization seem more attractive in later centuries, as the Unified Earth Government would sign off on a colony ship program that was revealed in 2310 to ease the burden on the ailing home world. This would not have been possible without the invention of the Slipspace Shaw-Fujikawa drive in the late 2200s, which allowed the ships to travel far greater distances than ever before.

It took 52 years before the first colony ship, the Odyssey, was launched, and what became the so-called Inner Colonies were not fully colonized until the end of the 24th century. The apex of human colonization would come in 2492, when more then 800 worlds were inside UNSC territory and a handful of them were under development or had already developed into colonies. By this time, a ring of Outer Colonies was providing the UEG with the raw materials that made the macro-economy work; the political power, however, remained with the aforementioned Inner Colonies. The massive difference in wealth distribution and political power, which became a hallmark of humanity by this period, led to new threats of secession from the outer ring. Fearing the consequences of the breakup of the interstellar empire and seeing the benefits of avoiding all-out war to defend their hold on the colonies, the Earth government would embark on the SPARTAN-Is, the predecessors to the SPARTAN-II program in 2491, beginning with the ORION Project.

The Human-Covenant War
2525 marked the most important turning point in human history; it would mark the beginning of the great technological advancement, the unification of a divided and fractured human race, and the first contact of humanity and an extra-terrestrial intelligence, the Covenant. It would also see a majority of the Earth government's colony worlds destroyed, and billions of colonists and military personnel slaughtered by orbital plasma bombardment and planetary invasion, known as glassing. Thus began the Human-Covenant War with the First Battle of Harvest.

Stemming from the chance encounter of human and Covenant forces at Harvest, the first contact made between humanity and the Covenant involved the ship Minor Transgression, and was less peaceful than the second contact made between the two factions. A less aggressive meeting between representatives of the two factions took place on the fields of Harvest, but the peaceful meeting soon turned into a blood bath, with the Covenant claiming the planet for the numerous "Forerunner relics" present (unaware that the humans are the relics), slaughtering most of the colony's population.

On April 20, a scout ship, the CMA sent in a scout ship, the Argo, to investigate the cessation of communications between Harvest and the rest of the UEG's colonies. Before being destroyed by Covenant forces, it discovered that everything on the planet had been completely incinerated, and the surface covered by fields of magma, leaving nothing alive. Soon after, Battlegroup 4, consisting of the frigates CMA Arabia and Vostok and the destroyer CMA Heracles, were sent to investigate. On October 7, the battle group dropped out of Slipspace and to Harvest. In orbit around the remains of the colony world was a single alien ship which proceeded to attack the battle group, destroying all the ships except one. Intercepted communications identified the enemy as the Covenant, a caste-driven, theological organization made up of several alien species. The message "Your destruction is the will of the gods...and we are their instrument" was broadcast in perfect English.

Since the later Second Battle of Harvest in 2526, where a huge human fleet led by Vice Admiral Preston Cole barely won against a smaller Covenant fleet in a symbolic "victory" for humanity, the humans' grip on their territories declined significantly in the course of their struggle. The Covenant had managed to capture the majority, if not all of the Outer Colonies, and a portion of the Inner Colonies.

By this time, the UNSC overrode the UEG, and thus the central civilian authority throughout the human worlds and Earth itself. Although the central government was more willing to step down, the Colonial Administration was far more reluctant to this idea, and thus the UNSC stripped it of most of its power. By the middle to late stages of the war, the government of humanity could be more accurately described as an "emergency military" government.

By 2552, the UNSC, outnumbered and outgunned, had managed to slow down the Covenant's inexorable progress through former human space, but the situation was dire. In desperation, HIGHCOM ordered a high-risk op, sending the SPARTAN-II super soldiers, the best soldiers ever fielded by humanity, to insert into Covenant space, capture a high-ranking Prophet, and return to UNSC space in an attempt to ransom for a truce. Before the operation began, the Covenant found and destroyed the planet Reach, killing most of the Spartans and a large portion of the UNSCDF, inadvertently stopping the operation and rendering most of the SPARTANs MIA.

A single ship, the UNSC Pillar of Autumn managed to escape the planet, with two SPARTANs on board, Linda-058, who was presumably dead in the Fall of Reach and the John-117. The ship followed coordinates derived by the A.I. Cortana to a ringworld known as Halo. There John-117 destroyed a large Covenant fleet and the ringworld itself. He also encountered a parasitic lifeform known as the Flood, the species that the ring, Halo, had been built to starve. The major side-effect of the activation of the ring would lead to the extinction of all life within three radii of the galactic center. John-117 destroyed the ring, believing it to be too powerful, by detonation of the reactor of the Pillar of Autumn. After hijacking a Covenant Flagship known as the Ascendant Justice, the SPARTAN reunited with the remaining survivors from Installation 04 and the destruction of Reach and attacked a force of Covenant ships and a large Covenant space docking station in Operation: FIRST STRIKE, one of the most successful UNSC operations against the Covenant in the entire war.

By October of 2552, the Covenant had haphazardly discovered the position of the human home world, Earth, and sent a preliminary task force there, believing it to be the location of the Ark, an ancient Forerunner relic. They encountered staunch resistance, and were initially fended off. Further complications arose from the political and religious crisis that emerged in the wake of a UNSC operation to assassinate the Prophet of Regret, and the secession of the Sangheili from the hegemony, leading to the Covenant Civil War, further throwing the Covenant into chaos. Nevertheless, by November, what was left of the Covenant Loyalists had subjugated large parts of Africa, devastating much of the planet. Only their retreat through a Forerunner portal in Africa, and the arrival of the Sangheili Fleet, stopped the utter destruction of the UNSC and Earth itself.

The UNSC and Covenant Separatist forces launched a joint operation to destroy the Covenant Loyalists once and for all at the Ark, stopping the installation from firing the Halos, killing the Covenant's last remaining leader, the Prophet of Truth, and destroying the bulk of the Loyalists' remaining forces. On March 3, 2553, the Human-Covenant War officially ended in a victory for the UNSC and the Covenant Separatists, but at a high price, with most major military outposts destroyed except for Earth as well as many colonies (although it seems that most of the colony worlds were not glassed during the war, with only seventy-six worlds known to have been totally destroyed). It is presumed that millions of UNSC personnel and an estimate twenty-three billion human civilians had been killed from 2525-2553.

Reconstruction
Since 2553, the UNSC has engaged in an extensive period of reconstruction in order to restore stability to the shattered remnants of human space. The UNSC has moved to reclaim those worlds that were not completely destroyed during the Human-Covenant War. By 2589, the former human stronghold of Reach had been restored and resettled by the UNSC. The UNSC also maintains its earlier truce with the members of the Covenant Separatists.

Economy
The UNSC uses the United Nations Credit monetary unit to organize its economical stability by selling or buying military equipment, supplies and costs for shipping, etc. The U.N. Credit was implemented by the United Nations some time before its dissolution and replacement with the Unified Earth Government in 2164. For transporting food and raw materials between colonies, the UNSC maintains a merchant navy, run by the Department of Commercial Shipping.

Defense
Defense of UEG colonies are run by the United Nation Space Command DefensesForce. The Defense Force was involved heavily in the Human Covanted War.

The UNSCDF is run by the UNSC SecurityCouncil, with the professional head being UNSC highCommand, based on Earth. Control is exercised through regional CENTCOMs, which have responsibility over certain areas of space. The Navy houses the divisions of UNSC Marine Corps (including the special forces branch of the UNSC Marines known as Orbital Drop Shock Troopers), Office of Naval Intelligence (ONI), and the Fleet. The UNSC Army and UNSC Air Force maintain garrisons on colony worlds. When certain rebellious factions began to rise in the late 2510s, the UNSC was forced to police its protected colonies tirelessly to keep privateers and pirates from raiding the colonies and any UNSC ships.

The UNSC also developed the SPARTAN-II and the SPARTAN-III programs. The SPARTAN-II program being the long-term, high powered solution to a problem that they tried to preserve, an example being John 117, a.k.a. the Master Chief. The SPARTAN-III program on the other hand was the fire-and-forget answer to the problem and therefore, were expendable, a few examples of SPARTAN-III's are most of NOBLE team, except for Jorge.

Unlike the Covenant, UNSC military technology is still based on comparatively primitive mechanisms - projectile weaponry, wheeled vehicles, and combustion engines. The UNSC's grasp of scientific concepts is far more advanced than the Covenant, but turning these concepts into functional machinery has proven more problematic. Recently, the UNSC has introduced a variety of Covenant-derived technologies into their arsenal: gravity plating aboard ships, energy shields to protect SPARTAN-II soldiers, and limited use of directed energy weapons, usually lasers, for example, the Weapon/Anti-Vehicle Model 6 Grindell/Galilean Nonlinear Rifle (SPARTAN Laser), though the Covenant still retain their technological advantage.

UNSC starship weaponry is based around missiles and Magnetic Accelerator Cannons. Their technological inferiority in the face of the Covenant means that it was often necessary for the UNSC to have a three-to-one numerical advantage against them in ship-to-ship combat. The UNSC also possesses a weapon of mass destruction in the form of the NOVA bomb.

The UNSC also appears to maintain a seaborne surface navy on planets with large bodies of water, such as Earth. At the very least, they had aircraft carriers available to provide air support in the form of Pelicans and F99 UCAVs.An approximate map of significant UNSC systems.

Sphere of influence
Human-occupied systems were known to encompass a relatively wide radius of the Orion Arm of the Milky Way Galaxy, in various stages of colonization, from the well developed Inner Colonies to the relatively recent and struggling Outer Colonies. Thus far, 74 colonies have been referenced. Most of these colonies, under the influence of the UEG, were therefore controlled militarily by the UNSC.

The territory encompassed by the Inner Colonies seemed to stretch in at least a 10.5-light year radius around Earth, and the Outer Colonies beyond that. By 2468, the outermost colony was Harvest, at twelve light years from Earth - later, colonies were founded well beyond in the Outer Colonies. The furthest known colony is Beta Centauri, at 350 light years away. Colonies may have been settled after Harvest, or founded during the Human-Covenant War.

The UNSC's influence over these worlds were greatly reduced by the Covenant during the Human-Covenant War, with only Earth and a few scattered colonies left mostly intact by the end of the conflict in 2552. Since the end of the conflict, the UNSC is working to restore its galactic territories and has even recolonized some of its former worlds including Reach