UNSC-CMA Cold War

The UNSC-CMA Cold War was an extended period of tension between the armed forces of the United Nations Space Command, aligned with the United Earth Government, and those allied with the Colonial Military Authority.

Background
The conclusion of the Inner Colony Wars in the 2390s saw a notable momentum shift in the direction of interstellar colonisation. Excesses perpetrated by the CMA in containing the conflicts and a growing UNSC presence in such matters saw the revision of the UN Colonial Charter in 2390, and numerous reforms to the governmental structures of both the United Earth Government and Colonial Administration Authority over the ensuing decade. As part of these reforms, an event later referred to as the Handover was planned with a central principle; the growing expertise of the UNSC in dealing with matters of interstellar concern was deemed sufficient that they take over such duties from the CMA - who had proven themselves insufficiently capable in the eyes of many during the previous decades of conflict. Some opinions felt that the CMA had no reason to exist any longer and that their assets and personnel should be in whole merged with those of the UNSC; others felt that the reverse was true. Many in both organisations feared for their respective futures.

In the original UN Colonial Charter adjustments, the UNSC were granted the administration of several systems in the immediate surrounding of Sol - notably Epsilon Eridani and Alpha Centauri, and the formalisation of the SolCore region of space. This move was unpopular with the CMA, with the primary transit hub and growing industrial and ship-building base of humanity surrendered to UNSC authority. Nonetheless, throughout the early 2400s the reconstruction of those inner colonies most hit by the war and the growing presence of humanity in the Outer Colonies saw a period of relative peace emerge throughout the human sphere, later coined Pax Humana. The majority of the Inner Colonies bounced back from their hardships of the Inner Colony Wars stronger than ever, rebuilding their infrastructure to take advantage of new advances in FTL technology and ever-more rich resource imports from the Outer Colonies. Those dissatisfied with life in the Inner Colonies began to take to the stars themselves, founding by the 2420s the "Second-Wave Colonies" - Outer Colony worlds seeded by colonists originating from the Inner Colonists. During this time period, the UNSC continued to slowly push their presence further into the Inner Colonies as they assisted in reconstruction and policing efforts, and for a time many proclaimed this new era as an "End of History" - in which humanity would continuously spread across the stars and usher in a permanent peace.

Although this era was one of widespread peace, tensions still subtly remained under the surface. A small minority of worlds involved in the Inner Colony Wars were never able to rebuild to their previous heights, with logistics issues continuing to plague the settlements for decades after the conflict's secession. On a small minority of worlds, revolutions and riots and - in one case - a small civil war were fought, though swift action by the UNSC prevented these conflicts from escalating and were ended mostly-without incident. As the UNSC continued to take on more responsibilities in the regions surrounding SolCore, they soon began to find their existing fleets of spacecraft insufficient to tackle the tasks at hand. The UNSC began to increasingly commission private industry to assist their operations.

UNSC-CMA naval arms race
By the 2430s, the situation began to grow ever-more grim for the admiralty of the UNSC. Much of the UNSC fleet was outdated, and still majority-comprised of vessels built for policing one star system. Most didn't have slipspace drives, or relied on unreliable post-retrofits for FTL operations. It was common practice for UNSC ships in drydock to remove their slipspace drives for transfer to another vessel to help facilitate ongoing interstellar travel, an extremely risky operation resulting in several close-calls with the wholesale destruction of spaceports. Public opinion began to increasingly turn against the UNSC, and questions were now raised as to whether the CMA should in-fact take over the UNSC's duties as the primary military arm of the UEG. Simultaneously, the sheer disparity of ships led naval strategists to a common conclusion; if the CMA or Outer Colonies wanted to secede from Earth's rule, there was little the UNSC could do to stop them. Even a strike on Sol was considered possible, due to the overstretched nature of the UNSC in the Inner Colonies.

Faced with these realisations, the UNSC and its naval intelligence division began a propaganda campaign not dissimilar in nature to those of the CMA, painting a future in which rebellion was possible and Earth could well-be attacked and bombarded, in an effort to increase recruitment and begin a naval modernisation project. Throughout the 2440s and 2450s, the situation slowly-but-surely began to improve, and the UNSC were able to begin adapting for the emerging trend of paragravity in ship design, beginning the construction of vessels with horizontal deck plans rather than the "skyscraper" configurations of previous generations. This naval buildup is commonly cited as the start of the UNSC-CMA naval arms race and the cold war, though some historians (notably criticised as too reliant on the Inner Colony exceptionalism narrative) view the CMA as the aggressors in this conflict.

Officially, the 2469 CMA Fleet Modernisation was created in response to the ever-growing amount of star systems becoming settled by humanity; the exponentially-increasing distance needing to be patrolled by the CMA meant that they had a constant need for more ships and personnel. However, a secondary reason oft-cited by the UNSC is the fleet modernisation was a response to the UNSC's own efforts in previous decades, and the first such action seen as a direct response to the other. As such, a massive naval arms race begun in earnest on both sides and attitudes grew increasingly sour. This era saw the two sides diverge massively in their naval doctrines, with the UNSC favouring larger fleets of smaller ships that could be mass-produced in a short amount of time, while the CMA responded with a large capital ship program and fewer numbers of smaller patrol vessels. Both sides began to increasingly militarise the "Mid-Rim" colonies on the borders of their respective territories, conducting large naval exercises with the aim of flexing their respective naval mights and testing yet-unproven space warfare theories - no major space warfare had taken place since the Interplanetary Wars of the 22nd century and as such, nearly-all space warfare strategies were purely theoretical.

In 2478, the UNSC unveiled the, a revolutionary ship and officially classed as a carrier escort. However, the Mirata carried enough armaments to effectively outgun all previous designs while also stocking an armour shell of Titanium-A1 battleplate allowing it to retain a speed normally reserved for much lighter ships. The 2480s saw the CMA respond in kind with the introduction of the and  lines.

Hydra System Massacres
Taking place between 2467 and 2474, the Hydra System Massacres were a brutal civil war fought primarily between the Hydra system's twin worlds of Samarkand and Bomogin, with various third parties throughout the system. The conflicts were a mess of tangled political allegiances and competing causes, caused by decades of inter-planetary rivalry dating back to the Inner Colony Wars and the UN Colonial Charter revisions. These conflicts saw a mass amount of war crimes including forced labour and genocide occur on a scale not matched since the Interplanetary Wars, largely perpetrated by the various regional actors of the Hydra system. For seven years, messy fighting took place across the system, ultimately leading to the deployment of a CMA task force in an attempt to control the situation and prevent it spiralling into a new interstellar conflict.

The Hydra system had one major border, the Eta Corvi system and its major CMA naval base on Kingston. As such, the UNSC had backed the Bomogin military junta and turned a blind eye to its regime in exchange for its security as a potential ally should a conflict break out; the proximity of Bomogin would allow the UNSC to quickly take control of the Kingston base and project power deep into the Hydra Region. As such, when conflict in the Hydra system broke out, the CMA initially intervened on the side of the Samarkans (having previously armed and aided the Samarkans in the preceding years) due to the decried actions of the Bomogin government, assisting their forces in launching strikes against the Bomogans and providing materiel aid. The Samarkan coalition later broke down to infighting amongst their constituent factions, marking the start of a bloody guerilla war and the CMA assuming the role of peacekeepers. Due to the long-distance communication times, the CMA task force in the system was largely acting without communication with high command, resulting in various units intervening to prevent massacres despite the aim of the commanders to not aggravate the local factions. This independent spirit ultimately escalated in the space theatre, with CMA warships using space-borne nuclear weapons to destroy a handful of asteroid bases and spacecraft, where conventional doctrine would dictate for these assets to be boarded and relevant prisoners taken.

The excesses committed by both regional actors and the often heavy-handed nature of the CMA's peacekeeping efforts ultimately resulted in the deployment of a UNSC task force into the region to properly defuse the situation. The UNSC were initially welcomed by both sides of the conflict, due to their relieving the CMA of duty, though this welcome soon turned into further hostilities as the UNSC worked to enforce a total cease-fire, allying themselves with neither side of the conflict. This response saw many of the dissident groups begin to rally under more unified banners preaching an anti-imperialist cause, largely unified of a wish to be rid of the governance of Earth even despite their own differences. Despite these setbacks, the UNSC were able to conduct a number of successful strikes on the major cities of the Bomogin-Samarkand system, ultimately restoring order to the urbanised regions and propping up a puppet government on Bomogin.

Initially, the Bomogin puppet government was simply intended to restore the political situation to its pre-war state, though pressure from the CAA soon revealed the excesses of the Bomogin regime to the world - and the legitimacy of the Samarkand cause. A settlement was reached in which both planets were granted equal representation in the larger political systems of the UEG, though the unstable situation forced the UNSC to keep its military occupation on both planets for decades after the official end of the Hydra System Massacres - constantly bogged-down in anti-insurgency warfare against groups often supplied by the CMA.

The Hydra system campaign was in many ways a landmark turning point for the wider direction of humanity, seeing a radical shift in doctrine for orbital troop deployments and a begin of a marked shift in character of the CMA's method of operations. Where before infantry and officers were encouraged to act independently, the Hydra system excesses proved that more regulation was needed for troops on the ground, and the CMA's operating forces became increasingly mired in red tape at the same time as morale plummeted due to the actions the CMA took to suppress what their soldiers saw as their own brethren in the colonies. The anti-Earth sentiment which united many of the disparate regional factions in the system was one of several touchstones that would later spread across the stars toward the end of the 25th century.

Proxy wars
As the cold war continued to quietly escalate, anti-imperial protests and diplomatic attempts at secession from the rule of Earth became increasingly more commonplace across the colonies, particularly (though not exclusively) the Outer Colony regions. Starting in 2475, protests began to turn into uprisings, with both the UNSC and CMA charged with putting down uprisings in their respective theatres. Many of these uprisings began to grow in scale, demonstrating a clear and growing opinion turning against remaining inside the Earth's sphere of influence. This era was particularly transformative for the CMA, seeing many of its personnel begin to defect to insurgent organisations on their homeworlds - CMA personnel began to commonly express frustrations at being deployed to suppress the colonies they were sworn to protect. This era of "brain drain" was devastating to the CMA as experienced officers quit the organisation en masse, resulting in ever-more unqualified leadership coming into command positions, while defectors inside the organisation began "losing" shipments of supplies - only for them to end up in the hands of rebel forces.

These uprisings across the colonies were played by both the UNSC and CMA as a whole, with both players supporting (openly and covertly) their preferred actors to prevent the other side from gaining an advantage. The last uprising was officially put-down in 2485 though rebel sentiment still remained. In 2487, the Secessionist Union was founded and issued an ultimatum to the government of Earth - demanding total independence for all colonies across the stars who voted for it. Several coalitions such as the Via Casilina Community began to more closely-align their political, economic and military alliances as tensions began to flare. The Secessionist Union's declaration was largely dismissed on Earth, though some new amendments to the UN Colonial Charter were granted, which helped cool tensions slightly. Nonetheless, this was seen as a pittance by the colonies, who continued submitting their formal requests for independence. 2491 saw the publication of the Carver Findings and the infamous Carver's Maxim, declaring that if immediate action was not taken, humanity would find itself embroiled in an interstellar war of apocalyptic proportions. While dismissed by many as an example of radical terra-centrism, the report was taken seriously by officials within the UNSC high command and a more outwardly militaristic stance was taken against what was now assumed to be an inevitable military conflict.

The end of the CMA
In 2492, decades of tensions on the colony of Far Isle flared up as they had across a dozen other worlds. Initially beginning as a squabble between various generations of colonists soon blossomed into a messy ground conflict culminating in the bombing of the planet's under-construction space elevator. The CMA was deployed onto Far Isle in a peacekeeping role, though their efforts were largely inconsequential due to myriad factors. Riots in the capital city saw the storming of the UEG embassy on the planet, and the death of over a hundred UEG staff and UNSC soldiers. In response, the UNSC deployed a task force to bring order to the planet, now granted the authority to use more extreme force as per the Carver Findings. As the months went on, the Marine deployment found itself slowly ever-more overburdened, ultimately seeing a rapid escalation of events culminating in the deployment of nuclear weapons on the planet and the declaration of Code BANDERSNATCH.

After decades of proxy war between the UNSC and CMA, Far Isle proved to be the spark that finally ignited widespread rebellion across the colonies. Almost overnight, rebel sentiment turned violent and the Secessionist Union saw a massive increase in recruitment. The Callisto Incident two years later saw the Secessionist Union begin conducting coordinated attacks on a number of worlds including Eridanus II and Levosia, though in many cases Secessionist forces were welcomed with open arms by the planetary populaces. As the rebellion grew into the Insurrection, the UNSC and CMA found their previous hostilities somewhat forgotten as both began to conduct mass-scale counterinsurgency operations particularly against the core Secessionist Union worlds, and both co-operated in the reactivation of Project ORION. Despite this, the CMA was still riddled with traitors and double-agents, leading to a full-scale crackdown in 2496, ultimately seeing the CMA's funnelling of arms and intel to the rebellion largely-cease - forcing the Secessionists to begin adopting more guerrilla warfare tactics to fight the UNSC-CMA alliance. The outing of rebel infiltration within the CMA's highest echelons resulted in the CMA largely being stripped of its power and funding, and ultimately reduced to patrolling the most distant frontier worlds and providing logistical support to the UNSC's operations.

This saw the end of the UNSC-CMA Cold War, as the CMA was stripped of almost all of its power and the UNSC took on nearly-all military duties for the United Earth Government. Nevertheless, the CMA as an organisation survived well into the 26th century, with the CMA Argo and the CMA's Battle Group 4 sent to investigate the Covenant destruction of Harvest in 2525. With the outset of the Human-Covenant War, the majority of the CMA's remaining assets were folded into the UNSC entirely and the CMA was reduced to little-more than back-line logistics roles with unarmed craft manned by personnel unfit for front-line service.

Aftermath
Ultimately, although the Cold War focused more on both the UNSC and CMA, it inadvertently led to the outbreak of the Insurrection in 2494. The war for civilian support had seen Outer Colonials building resentment towards Earth, especially as CMA propaganda had framed the UNSC as out-of-touch imperialists who did not have their best interests at heart. Their quality of life had steadily gotten worse and worse over the period, and not only had the UEG General Assembly forced the CAA to implement unpopular Directives, many of which favored Earth and Inner Colonist-based organizations. Rather, it was also because of the CMA's own actions. On multiple times, populations had reached out to them after corrupt politicians passed laws that violated their rights on a number of worlds, and in all but the most damning disregard of human rights, the CMA was loath to step in and provide aid. As a result, the Secessionist Union was formed as a united league of worlds that desired to part from the UEG's empire.

From a military and strategic point of view, the CMA had lost the Cold War, and the period had cost them dearly. Though they had succeeded in temporarily fending off efforts to dismantle their organization, they had been pushed out of the Inner Colonies, with all their bases and stations turned over to the UNSC. The CMA servicemen were also divided at all levels, with arguments breaking out between Loyalists, who wanted to continue reinforcing UEG laws, and Sympathizers, who desired to use their military might to throw off Earth-based control once and for all. Though neither side won out, it had significant consequences. The CMA's early counterinsurgency campaigns were weak, restrained, and directionless. They were eager to negotiate but not compromise, nor were they willing to fire upon the people they wanted to protect. In the few times they committed to that, it either backfired and gave insurgents plenty of propaganda, or failed to achieve anything thanks to sabotage from Sympathizers. Indeed, for all their fears of escalating the situation, they had only armed and fostered resentment against the UEG and their CAA puppets.

Perhaps the greatest legacy of the Cold War was in the naval sphere, where the competition between the two government militaries who mutually distrusted the other saw their fleets drastically evolve. Before it started, warships were generally unarmoured and had little ability to close in with each other, instead relying on modest numbers of super-long ranged missiles and strikecraft to wipe out their opponents in a single, massive, overwhelming strike. The introduction of Titanium-A battleplate, new mid-ranged naval coilguns, and improved slipspace drives throughout the Cold War brought with it the preference for ships that could slug it out at distances previously considered suicidially close, making spatial combatants far more desirable as capital ships. Oftentimes, such new spacecraft dwarfed the size of their Pax Humanan predecessors, with average class masses often doubling or even tripling in many cases. In many ways, the Cold War was credited with beginning the process of modernising humanity's militaries for a 26th-century war, laying the foundations that inadvertedly prepared them for conflict with the Covenant.