- "By the time we realized they hit, half of my men were gone...."
- —an unknown commander during Operation: Hardline
Operation Hardline was an operation in which 428 UNSC marines attempted to destroy a series of covenant AA batteries in the jungles of the planet known as Kyrat. Combat reports showed heavy marine losses and at least 2 covenant AA guns destroyed.
During the invasion of Kyrat in 2558, the covenant placed series of AA batteries. Multiple Marine battalions were tasked in destroying the defensive batteries. Most did not succeed and were either completley wiped out or were overrun and forced to fall back.