Treaty of 2552

"I promise this to every man, woman and child on Earth and in its colonies. While we will continue to strive for a peaceful coexistence with other species, humanity will never again allow itself to be the victim of aggression. This is the moment we start to reclaim our rightful place in the universe."

- President Ruth Charet's inaugural speech

The Treaty of 2552, also known as the Ceasefire of 2552, is an agreement of peace between the Unified Earth Government and the Swords of Sanghelios—and perhaps, humanity and the Sangheili as a whole—that brought an end to the Human-Covenant War. Although the war officially ended on March 3, 2553, the fighting had largely subsided by December 11, 2552. The treaty's title refers to the peace agreement and alliance developed between the Sangheili and the United Nations Space Command in 2552, although the Treaty of 2552 was formally ratified in February 2553.

Although the UEG did not initially formalize a treaty with the Kig-Yar —and presumably other former client species of the Covenant—as of March 2553, a majority of the species have seemingly agreed to peace with humanity. However, humanity and the Sangheili continue to trade with the Kig-Yar. The UEG and the Swords of Sanghelios attempted to form a treaty with the Jiralhanae on Ealen IV in March of 2558, but these peace talks were disrupted by a mercenary group. The era following the war is referred to as the Treaty period by some individuals.

Terms
The Treaty of 2552 declared the cease of hostilities between humanity and the Sangheili. The peace treaty forbids any party of the agreement from landing on the remains of Installation 04 and a 500 light-second exclusion zone was established around Threshold, with both Sangheili and human warships patrolling the region. However, Sangheili and UNSC forces continue to monitor Installation 07 and worked together to prevent potential Flood outbreaks, while the UNSC has established research facilities orbiting Installations 03 and 05. Regions of space held cooperatively between the Unified Earth Government and the Swords of Sanghelios, called Joint Occupation Zones, were established, as were research and military pacts formed between the two governments. Terrorist groups and splinter cells continued to directly violate the treaty's terms by attacking the parties of the treaty.

History
The Human-Covenant War lasted just over twenty-eight years. The war, primarily occurring in the Orion Arm of the Milky Way galaxy, led to the destruction of a majority of the Unified Earth Government's colonies, over 23 billion human causalities, and the dissolution of the massive Covenant empire. In the final year of the war, the remaining Hierarchs of the Covenant replaced the Sangheili with the Jiralhanae in an effort to gain an unquestioning military. This led to the Great Schism and the fragmentation of the Covenant, as many new factions were formed. The most organized faction was led by Arbiter Thel 'Vadam and Special Operations Commander Rtas 'Vadum. Recognizing that the Sangheili were too disorganized to properly seek revenge against the Covenant, 'Vadam and 'Vadum reluctantly agreed to work together with members of the UEG's United Nations Space Command to defeat the Covenant. Initially, the truce between the Sangheili and humans was very tenuous; at least one faction even intended to continue to wipe out humanity. Ultimately, the two groups were able to work together to dissolve the Covenant at Installation 00 and stop a potential galactic Flood outbreak. With the war over, relative peace was finally seen by humanity for the first time in years. Fleet Admiral Lord Terrence Hood was invited to Sanghelios by the Arbiter to formalize the peace treaty between the UEG and newly established Swords of Sanghelios, ratifying the Treaty of 2552. The official treaty was signed and ratified by Hood and 'Vadam. On March 3, 2553, 'Vadam and 'Vadum were invited to Earth for the Voi Memorial, a tribute to the soldiers that lost their lives in the war.

After the signing of the treaty, the Arbiter traveled across Sanghelios and visited each state to make his case for permanent peace with humanity throughout early 2553. He reminded the Sangheili that if anyone disagreed with him, they could attempt an assassination as per Sangheili tradition. In Mdama, although many keep elders did not agree with 'Vadam's ideals and beliefs, Kaidon Levu 'Mdama pledged that his state would side with him for the good of the Sangheili.

Later, after the UNSC helped 'Vadam fend off the attack by the Servants of the Abiding Truth, the Arbiter was in talks to visit the. The Swords of Sanghelios also participated in simulation exercises with SPARTAN-IV forces as part of the ANVIL initiative. The UNSC also provided security during peace talks between the Arbiter's faction and Lydus' clan in 2558.

Reactions and controversies
Although the reaction to the treaty was mainly positive on both sides, many humans and Sangheili were still opposed to peace between the species. Despite harboring dislike for the species, most humans accepted the treaty and saw it as a step in the right direction. However, groups such as Sapien Sunrise, an extremist xenophobic organization, were heavily opposed to peace with the Sangheili. Based in the Outer Colonies, Sapien Sunrise had access to military hardware, and in 2558 used it to infiltrate a peace delegation on Biko, planning to assassinate the human ambassadors and blame it on the Sangheili. However, their plan failed when Spartan John-117 killed the terrorists and rescued most of the delegation.

The treaty was violated by the Office of Naval Intelligence in 2553 when the covert intelligence unit Kilo-Five was tasked with inciting insurrection between various Sangheili factions to keep the Sangheili from gaining strength, with ONI directly violating the treaty in March 2553, when the, captained by Serin Osman, destroyed a number of 'Vadam's ships by posing as a Kig-Yar pirate ship.

Although Thel 'Vadam gained a strong following through his cooperation with humanity, many Sangheili believed he betrayed his people. As with humanity, Sangheili extremist organizations began to form. One such group was led by Otar 'Bemet, who in 2555, conspired to kill the Arbiter with weapons they were planning to steal from a manufacturing facility in the Qish'tani region of Tolvuus, Sanghelios. The plan failed, however, when one of the Arbiters soldiers, Usze 'Taham, killed the conspirators.

List of appearances

 * Halo: Glasslands
 * Halo: The Thursday War
 * Halo 4
 * Halo: Spartan Assault
 * Halo: Mortal Dictata
 * Halo: Nightfall
 * Halo: Hunters in the Dark
 * Halo Online