‘Restrepo’ Combat Commander Tells NATO Scientists How Sleep Loss Shapes the Battlefield

Army Col. Daniel Kearney joined a USU summit on battlefield fatigue with scientists from six NATO nations.

August 27, 2026 by Zachary Willis

Scientists from six NATO countries met at the Uniformed Services University of the Health Sciences (USU) on July 6, 2026, for a summit on battlefield fatigue and its effect on troop performance. Army Col. Daniel Kearney, who commanded an infantry company through 15 months of combat in Afghanistan's Korengal Valley, offered a firsthand perspective on what sleep deprivation does to a leader's judgment when the fighting doesn't pause for rest.

Kearney's deployment as a captain with Battle Company, 2nd Battalion, 503rd Infantry Regiment, was the subject of Restrepo, the 2010 documentary that won the Grand Jury Prize at the Sundance Film Festival and earned a nomination for best documentary feature at the 83rd Academy Awards. He returned to USU this summer at the invitation of Dr. Francis O'Connor, a retired Army colonel, professor of Military and Emergency Medicine and medical director of the Consortium for Health and Military Performance (CHAMP), now part of Advanced Research in Military Optimization, Readiness, and Rehabilitation (ARMORR).

The event, hosted by USU's Department of Military and Emergency Medicine, paired Kearney's operational background with a gathering of scientists focused on fatigue mitigation, sleep and traumatic brain injury, including the foreign delegations. Kearney, who has spent nearly seven years of his career deployed to combat environments, walked the group through the physical and mental toll of continuous decision-making without sleep. He also stressed that surviving fatigue isn't something a leader manages alone.

"He emphasized the importance of both the leader and the team in mitigating fatigue (the group being stronger than the individual)," O'Connor explained.

Kearney also described how his units maintained physical readiness with little time or space to train in the field, but training wasn't the whole picture. Rest counted just as much, O'Connor said, describing sleep efficiency as a factor commanders often discount next to fitness.

This wasn't Kearney's first visit to USU. O'Connor said the university previously hosted Kearney alongside journalist Sebastian Junger, who co-directed Restrepo and wrote its companion book, War, for a discussion with medical students. That earlier visit shaped why O'Connor asked Kearney back this time.

"We wanted Col. Kearney there to give the researchers a real perspective on combat and combat fatigue," O'Connor said.

For O'Connor, that firsthand account is the point. Data on sleep loss matters, but so does hearing from someone who led troops through months of it. Kearney's experience put a human face on the science - what sleep loss looks like when the mission doesn't stop and the person making the decisions can't simply step away and rest.