The Last Good Man by Linda Nagata is $1.60 at Amazon US.
Spoiler:
Scarred by war, in pursuit of truth: Army veteran True Brighton left the service when the development of robotic helicopters made her training as a pilot obsolete. Now she works at Requisite Operations, a private military company established by friend and former Special Ops soldier Lincoln Han. ReqOp has embraced the new technologies. Robotics, big data, and artificial intelligence are all tools used to augment the skills of veteran warfighters-for-hire. But the tragedy of war is still measured in human casualties, and when True makes a chance discovery during a rescue mission, old wounds are ripped open. She's left questioning what she knows of the past, and resolves to pursue the truth, whatever the cost.
The Last Good Man is a powerful, complex, and very human tale.