Operation: ABLE SENTRY

Next:	Operation: PHALANX
Operation: ABLE SENTRY
Conflict:	Human-Covenant War
Date:	Between 2531 and 2552
Location:	Circinius IV, Circinius system

Operation: ABLE SENTRY was an operation of the United Nations Space Command on Circinius IV during the Human-Covenant War between 2531 and 2552. The operation saw the deployment of a unit of UNSC Marines—including Edward Buck—to provide force reconnaissance for Operation: PHALANX, an operation carried out by Spartan-IIs to evacuate civilians and observe Covenant invasion patterns on the planet.^[1]

Trivia

While John-117 and Spartan-IIs helped surviving civilians evacuate, the Battle of Circinius IV resulted in the entire population, with the exception of Hestati squad, being annihilated.^[2] This creates a contradiction.

^ ^a ^b ^c ^d ^e Halo 5: Guardians Limited Edition, Spartan Locke's Classified Orders
^ Halo 4: Forward Unto Dawn - John-117: "You're the only survivors." Michael Sullivan: "In the school?" John-117: "On the planet."