JANUARY 14, 2026 – From the littorals of the Indo-Pacific to the familiar training grounds of Southern California, 2025 was a year defined by action for I Marine Expeditionary Force. As America’s crisis response force, the Marines and Sailors of I MEF consistently demonstrated their commitment to being forward-deployed, combat-ready and prepared to answer the nation’s call at a moment’s notice.
“This year, the Marines and Sailors of I MEF met every challenge head-on, proving that we are ready, engaged, and if called upon, will fight and win, Our training and operations across the globe have not only sharpened our warfighting edge but have also strengthened the bonds we share with our allies and partners.” Lt. Gen. Christian Wortman, commanding general of I MEF.
Throughout 2025, I MEF translated intent into action through a persistent presence in the Indo-Pacific, recertifying as a joint task force headquarters, continued integration with the Navy, innovation in preparation for the next fight, and support to interagency partners in defense of the homeland.
Persistent presence in the Indo-Pacific
Forward presence and campaigning were central to I MEF’s efforts across the Indo-Pacific. Marine Rotational Force-Darwin and Marine Rotational Force-Southeast Asia ensured a combat-credible command element remained forward-deployed, training alongside allies and partners, and responding to natural disasters.
In 2025, MRF-D demonstrated what it means to be a forward-postured, stand-in force, capable of deterring, shaping, and responding across the Indo-Pacific. MRF-D 25.3 transformed its rotational presence in northern Australia into a deliberate operational campaign, aligning training, exercises, and real-world missions to reinforce combat credibility and regional responsiveness. That adaptability was proven as MRF-D rapidly transitioned from exercise Talisman Sabre in Australia to urgent lifesaving support in the Philippines following monsoon rains and tropical storms. Operating across extended distances and challenging weather conditions, MRF-D delivered critical support to affected communities while coordinating closely with host-nation authorities. The lifesaving support reinforced that readiness is not confined to training environments – it is proven through action when lives are at stake.
As MRF-D redeployed from Australia, I MEF sustained its forward presence through the deployment of MRF-SEA. Operating with a smaller force, MRF-SEA demonstrated how tailored Marine formations can remain forward, lethal, and effective. MRF-SEA participated in a series of multilateral exercises across Southeast Asia, focusing on maritime security, expeditionary operations, and crisis response. Like MRF-D, MRF-SEA quickly transitioned to providing lifesaving support following back-to-back typhoons hitting the Philippines.
Together, MRF-D and MRF-SEA illustrated I MEF’s ability to maintain a persistent presence in the region, demonstrating the U.S. commitment to a free and open Indo-Pacific.
Recertification as a JTF HQ
I MEF continued its annual participation in Exercise Balikatan in 2025, executing a full battle test alongside Armed Forces of the Philippines partners and being recertified as a joint task force-capable headquarters, validating our ability to plan, synchronize, and command joint and combined forces in crisis or conflict. The I MEF headquarters demonstrated disciplined mission command, integrating joint fires, sustainment, intelligence, and maneuver across a complex operational battlespace. Balikatan confirmed I MEF’s readiness to lead at the operational level – not only deploying forces forward, but commanding them decisively when required.
This certification was not an isolated achievement, but the culmination of two years of deliberate preparation and training milestones. Lessons learned throughout the continuum made the I MEF headquarters’ ability to command and control more capable and resilient, leading to its recertification.
Naval integration: From the littorals to the open ocean
Naval integration remained a defining strength in 2025. Through refinement of Amphibious Combat Vehicle employment, quarterly underway amphibious readiness training, Marine Expeditionary Unit generation, and fleet weeks, Marines and Sailors operated seamlessly as an integrated blue-green team with U.S. 3rd Fleet.
Seattle Seafair Fleet Week began with public engagement aboard the USS Somerset (LPD 25), where Marines showcased amphibious platforms to the public, including Amphibious Combat Vehicles and Marine aviation assets, highlighting the seamless integration of air, land, and sea capabilities. On the return sail to California, Marines and Sailors transitioned directly to QUART 25.4, conducting ship-to-shore landing drills and vehicle certifications, reinforcing proficiency in amphibious tasks that remain central to naval expeditionary operations.
The Navy–Marine Corps team’s cohesion was further demonstrated at the 250th Amphibious Capabilities Demonstration, where I MEF and U.S. 3rd Fleet came together in a synchronized, live-fire display of modern amphibious warfare. This large-scale demonstration celebrated both the Marine Corps’ 250th birthday and the enduring legacy of naval expeditionary power, integrating amphibious landings with naval surface maneuver, aviation operations, and joint fires. The blue-green team successfully planned, rehearsed, and exercised the command and control of more than 35 aircraft and a mix of surface and landing craft, conducting the largest mass landing of ACVs since the vehicle was fielded, as Marines and Sailors projected combat power from ship to shore with precision, speed, and coordination.
From public demonstrations that showcased amphibious power to rigorous underway training that sharpened ship-to-shore proficiency, Marines and Sailors strengthened the interoperability of the Navy-Marine Corps Team.
Innovation for the next fight
Innovation continued to be a driving force for I MEF in 2025, ensuring Marines remain lethal and adaptable in an evolving battlespace. This year featured deliberate efforts to integrate emerging technologies into Marine Corps operations and doctrine, demonstrated through I MEF’s participation in the Defense Innovation Unit’s GI Challenge. During this event, I MEF Marines partnered with DIU and industry leaders to evaluate commercial small unmanned aircraft systems (sUAS) under realistic conditions. Over a 12-day period, operators, leaders, and subject matter experts familiarized themselves with vendor-loaned sUAS systems and conducted scenario-based demonstrations to assess capability across setup, payload capacity, weather survivability, and performance in varied terrain and climates. These evaluations, including simulated contested environment operations, directly inform Department of War procurement decisions and accelerate integration of cost-effective drone technologies into the joint force.
This initiative exemplified I MEF’s broader commitment to innovation – combining frontline Marine expertise with industry solutions to meet emerging threats. By accelerating the evaluation and potential fielding of advanced drone systems, I MEF not only improved current capabilities but also helped pave the way for how unmanned platforms will be integrated into future combined arms operations.
Defense of the Homeland
Defending the homeland remains a fundamental responsibility for I MEF. In 2025, I MEF demonstrated its ability to respond rapidly in coordination with joint, interagency, and local partners. These missions underscored I MEF’s role as a force in readiness, prepared to provide scalable support when directed.
Marines surged within hours of tasking to support federal missions along the southern border, providing logistical capabilities that enabled partner agencies to carry out their responsibilities more effectively. Separately, I MEF stood prepared to assist civil authorities during periods of unrest in Southern California, ensuring that support was measured, professional, and focused on preserving safety and stability.
Whether responding to domestic emergencies or standing ready to deploy globally, I MEF remains postured to protect the Nation, support its interagency partners, and uphold the trust placed in the Marine Corps.
On to 2026
Whether operating forward with allies, commanding joint forces, projecting power from the sea, integrating cutting-edge technologies, or responding at home, I MEF remained ready to answer the Nation’s call in 2025. Looking ahead to 2026, I MEF will continue to lead from the front – further strengthening partnerships, refining combat-ready capabilities, and ensuring the force is prepared for the challenges and opportunities the future will bring. I MEF will remain, ready, engaged, and lethal.
Story by Capt. Gregory Dreibelbis
I Marine Expeditionary Force