CAMP PENDLETON, Calif. -- U.S. Marines and Sailors with I Marine Expeditionary Force, U.S. 3rd Fleet, and the U.S. Air Force’s 10th Air Force successfully concluded Exercise Steel Knight 25 on Dec. 14, completing two weeks of large-scale, distributed training across Southern California and Arizona.
The exercise, conducted at Marine Corps Base Camp Pendleton, Marine Corps Air Station Yuma, Beale Air Force Base, and San Clemente Island, tested I MEF’s ability to integrate naval, joint, and information capabilities in support of Indo-Pacific readiness and crisis response.
Steel Knight 25 certified the 5th Marine Regiment, 1st Marine Division, as the command element for the upcoming Marine Rotational Force–Darwin Marine Air Ground Task Force (MRF-D MAGTF) deployment. Throughout the exercise, Marines refined their ability to plan, deploy, and command forces across dispersed, contested environments while rehearsing crisis response missions including rapid deployment, forward command-and-control, and embassy reinforcement.
“At its core, Steel Knight is a division-led mission rehearsal exercise, meaning we take what we learn here to make us sharper for the future fight,” said Maj. Gen. Thomas Savage, Commanding General, 1st Marine Division. “Our Marines executed complex, multi-domain operations and integrated effectively with our MAGTF and joint partners—notably with the Air Force, which had the most robust presence to date at this year’s Steel Knight. Ultimately, Steel Knight 25 demonstrates exactly what makes the 1st Marine Division and the entire I Marine Expeditionary Force team the Marine Corps’ most combat-credible warfighting formation.”
As the lead headquarters, 1st Marine Division rehearsed decision-making, coordination, information advantage, and the employment of kill-web enabled command and control. Training also included long-range fires integration, distributed aviation operations, littoral mobility, and operations in a congested information environment.
For many junior Marines, the exercise provided their most advanced training to date.
"I have been so impressed across all levels of the 1st Marine Division," said Capt. Tyler Breeden, the staff judge advocate for the MRF-D MAGTF deploying in 2026. "From the high standards set by the Commanding General, to the professionalism demonstrated by the most junior Marine on the ground, we have shown our unique ability to respond to any crisis."
Logistics Marines played a central role in enabling distributed operations. With I MEF emphasizing contested logistics as a core warfighting requirement, Steel Knight allowed sustainment units to test their ability to support forces in degraded or denied environments.
“Supporting this exercise reinforced the need to innovate how we conduct distribution, sustainment, and protect our Marines across a dispersed battlespace,” said Maj. Jonathan Chavez, the operations officer with Combat Logistics Regiment 1. “Steel Knight enabled us to rehearse contested logistics in a realistic environment and provided a repetition on setting the conditions to meet Joint Force requirements in order to maneuver and win.”
Across all training venues, Steel Knight 25 reinforced I MEF’s ability to integrate naval expeditionary forces, joint air assets, and ground maneuver elements to support deterrence and crisis response in the Indo-Pacific.
For additional information, contact 1st Marine Division Communication Strategy and Operations at 1stmardiv_commstratsupport@usmc.mil.