Operation Tartarus

Operation Tartarus was a Blood Covenant assassination operation launched during the War of Vengeance against the United Nations Space Command.

Rationale
By 2560, the fifth year of the War of Vengeance, the Blood Covenant was in such dire straits that their leadership was willing to consider any option that might gain them the initiative, however briefly. With the New Covenant attacking them from one side, and the UNSC and Sangheili Armed Forces from the other, the Blood Covenant leadership was desperate to relieve the pressure from the UNSC/Sangheili alliance, so that more resources could be concentrated against the immeasurably more powerful New Covenant. With the loss of dozens of critical shipbuilding facilities, in addition to hundreds of vessels in the UNSC's Unrestricted Prowler Warfare campaign and in Operation: MACARTHUR, the Blood Covenant Navy was unable to launch a repeat of Operation Hammer lest they uncover a vital system and do themselves even more damage. Therefore, the only option they could think of was a political operation, specifically, the assassination of a key allied leader to throw the alliance into turmoil, slowing them down or even halting them completely. Given that they had an - admittedly shaky - understanding of Sangheili politics, the Blood Covenant chose not to attempt an assassination of significant Sangheili, knowing that someone just as capable or better would take the dead leader's place under the Sangheili's meritocratic principles, and so they chose to focus their efforts on removing the UNSC from the war. Jiralhanae understanding of human political structures and motivations has been understandably poor, given how far removed their own society is from the democratic institution that has served humanity's interstellar government needs. Their own society is a patriarchal kritocratic hierarchy, where males achieve power by defeating their superiors, moving up the chain of command as available posts become available. As such, it is not difficult to see how they concieved of Operation Tartarus.

Planning
To the Jiralhanae, the answer to the UNSC's continued involvement was simple - cut off the head of the snake, and the body dies. Fleet Admiral Lord Terrence Hood, 23rd Viscount Hood, effectively the benevolent military dictator of the UNSC during the Human-Covenant War, was seen as the most strategic candidate for removal. His influence upon the military was not inconsiderable, and without him, they believed, the UNSC would grind to a halt as rivals fought to fill his place, and the general populace would lose the will to fight. It was also meant to demonstrate to humanity that even their heroes were not invulnerable. While the Sangheili had cultivated a reliable spy network within the Brotherhood of Ruskt, with which the Blood Covenant had cool relations with, this would prove to be a double edged sword for them - the same network was used to gain information on Hood's projected locations and timetable, and an assassination fleet was rapidly assembled.

Assassination
What occurred, however, was certainly not the well-oiled precision of comparable UNSC and Sangheili operations. During a military inspection of the politically sensitive Middangeard ruins, the Blood Covenant appeared in orbit, engaging the limited colonial defence forces in orbit, blowing past the two orbital defence platforms and landing thousands of troops on the planet. In the ensuing ground combat, Hoods location was overrun, and the Admiral was killed by Jiralhanae forces before rescue teams could arrive. As response groups arrived to combat the enemy attack, a Sangheili delegation arrived in-system. Originally scheduled to take part in a ceremonial dedication on the colony, the fleet instead became part of a pincer formation, trapping the Blood Covenant fleet. While UNSC ships closed and engaged the main force, the Sangheili picked off stragglers and other ships attempting to flee. By the end of the space battle, not a single ship had escaped the slaughter. The ground battle was less smooth, and only the orbital support provided by the UNSC Navy and SAF Fleet allowed the local forces to retake the capital.

Aftermath
Technically, the operation was a decided success. It saw the death of a prominent military figure, as well as demonstrating that the Blood Covenant still had the capability to attack UNSC colonies, even while fighting a two-front war against the New Covenant and Sangheili Armed Forces. The response to it was decidedly different to that expected by the Blood Covenant. Rather than demoralising the UNSC, the attack served to infuriate humanity. Where before protests had been staged calling for the immediate withdrawal of human personnel and materiel from a war percieved by many as irrelevant, now public opinion swung back in the UNSC's favour, producing a public outcry and outrage. The UNSC would immediately step up its operations, increasing funding for special warfare projects, and mobilising the entire armed forces for the first time since the Human-Covenant War in the name of colonial security.