Operation: RED FLAG

"Assembled here tonight are all surviving Spartans save three, who are otherwise engaged on fields of combat too distant to be easily recalled. In the last decade of combat there have only been three KIAs and one Spartan too wounded to continue active duty. You are to be commended for having the best operational record of any unit in the fleet. It is very good to see you all again."

- Dr. Halsey beginning her briefing.

Operation: RED FLAG was a planned United Nations Space Command operation designed to put an end to the 27-year struggle of the Human-Covenant War. It was initiated by Naval Intelligence Section Three in mid-2552 as a desperate attempt to avert humanity's imminent defeat at the hands of the Covenant Empire; however, the operation was never carried out due to the Fall of Reach and the UNSC's subsequent retreat to Earth.

Operation
The operation was to be executed in four phases.


 * Phase One — The first objective of the operation consisted of the disabling and capture of a Covenant vessel. For the first phase, Dr. Halsey selected Captain Jacob Keyes for his exemplary performance during the Battle of Sigma Octanus IV, and his newly fitted cruiser.


 * Phase Two — Involving the boarding of the captured Covenant vessel by the SPARTAN-IIs, they would then neutralize the onboard defenses and take control of the ship. They, with help from a then-unidentified mission specialist, would then crack the navigation database of the ship and discover the location of the Covenant home world.


 * Phase Three — With the help of Cortana, the Spartans would then pilot the captured Covenant vessel to the Covenant homeworld.


 * Phase Four — The final phase of the operation involved the infiltration of the Covenant home world and the capture of a Covenant Prophet for negotiating purposes. The UNSC hoped that by capturing a Prophet and holding it hostage, they could force the Covenant into agreeing to a truce, thereby ending a war that the UNSC would most certainly have lost.

Results
Though the operation was never completed, it did introduce two pieces of technology: the AI Cortana and the MJOLNIR Mark V. These two items, used later by the Spartans, would be instrumental in the outcome of the war.

Despite the Fall of Reach, the loss of most of the SPARTAN-II force assigned to the operation, and the Battle of Installation 04, John-117 had every intention of continuing Operation: RED FLAG, despite arguments against it by Lieutenant Elias Haverson and Cortana. The seasoned Master Chief only agreed to not continue the mission once proper instructions were given by the Admiralty on Earth if RED FLAG was still an active endeavor by the UNSC.

Alternative
Ultimately, the plans would be canceled by a lack of resources and manpower. The Invasion of Earth began shortly after the remains of RED FLAG arrived back at the homeworld, effectively scrubbing any chances of a high-risk offensive by special warfare units accompanied by fleet support. However, events initiated within the ranks of the Hierarchs and High Council would provide a similar outcome to that envisioned by High Command and Naval Intelligence just months before. An ongoing feud between the increasing Jiralhanae threat encroaching on Sangheili commanders throughout the military planned by the Hierachs would ultimately culminate in it's fall, the Great Schism tore a rift between these two castes, with the former of the two species becoming the favored guardians of the Great Journey. Taking advantage of these brewing events, on November 2nd, 2552, the former Spartan leader of RED FLAG managed to infiltrate a heavily-occupied area on Installation 05 (Delta Halo), defeat a detachment of Sangheili Honor Guardsmen, and assassinate the High Prophet of Regret. Just days after during a Flood assault on High Charity, the High Prophet of Mercy was killed by the spreading infection in front of John-117.

A month later, a joint Human-Sangheili force of the Fleet of Retribution led by Lieutenant Commander Miranda Keyes began an operation to destroy the remaining command elements of the High Prophet of Truth and his fleet at the Citadel. This joint force destroyed a handful of Covenant infantry forces, in addition to their armor and aerial assets. The push to the Citadel ultimately led to end of the Human-Covenant War with the assassination of the Prophet of Truth by Arbiter Thel 'Vadam, with John-117 as witness. .

Though currently unknown, while the assassination of the three Hierarchs did result in the end of politically-organized major combat operations by the Covenant Empire, it's unknown if the military leaders of the Covenant's vast armies and fleets either surrendered or took part in a galactic-wide cease fire. However, pockets of Jiralhanae resistance did continue small-scale skirmishes against the Sangheili until the end of the decade.

List of appearances

 * Halo: The Fall of Reach
 * Halo: Reach
 * Dr. Halsey's personal journal