U.S. Soldiers assigned to the 3rd Battalion, 172nd Infantry Regiment (Mountain), 86th Infantry Brigade Combat Team (Mountain), Vermont National Guard participated in a combined arms live-fire exercise, May 29-31, 2025, during Immediate Response 25. Immediate Response 25 is a large-scale, joint exercise with NATO allies and partners taking place at the Krivolak Training Area in Krivolak, North Macedonia, May 26 to June 9, and is part of DEFENDER 25, the U.S. Army’s premier large-scale deployment exercise in Europe.

DEFENDER 25, Dynamic Employment of Forces to Europe for NATO Deterrence and Enhanced Readiness, demonstrates the U.S. Army’s capability to move troops and equipment across long distances, integrate with Allied forces, and project combat power across the European theater.

“These exercises are an opportunity for us to come together with partners from our NATO Allies and ensure that when we combine together in these larger numbers, we also have the interoperability it takes to do something like the combined arms exercise,” said U.S. Army Lt. Col. Nathan Fry, commander of the 3rd Battalion. “That we can mass all of our combat power together to get the job done.”

This live-fire event marked a critical milestone in DEFENDER 25’s Immediate Response phase, showcasing the ability of U.S. and NATO partner forces to rapidly deploy and execute complex combat operations alongside allies in strategic locations across Europe.

“All plans are great on paper, but until we actually get out and get to take part in these large exercises, we’ll never know what our allies are capable of,” said U.S. Army 1st Lt. Jason Anderson, a platoon leader with Delta Company. “How we all blend together and fit in, when we do need to work together in real military operations.”

The day and night CALFEX focused on joint tactical integration between the United States and Greece, emphasizing suppressive fire coordination, combined maneuvering, and precision strike capabilities using all available weapons systems and tactical assets.

“We conducted a live-fire exercise, culminating from a crawl, walk, run — dry, blank, live. The overall mission for us was to attack to control an objective for us to conduct follow-on missions and to open up lines of communication for other units,” said U.S. Army Staff Sgt. Trever Lacasse, a section leader in D Company. “I think it's important to do that progression from small unit level, up to these large-scale events with our NATO partners.”

The three-day event progressed through a crawl-walk-run approach, starting with dry runs, where the company ran through several iterations of the exercise before moving on to blank-fire iterations the following day. On the final day, the U.S. and Hellenic Armies executed a full live-fire assault exercise, executing day and night operations with a wide array of weapons systems and platforms, highlighting joint coordination, combined fires and real-time battlefield decision-making.

The culminating live-fire event featured coordinated fires and movement across multiple domains. Hellenic AH-64 Apache helicopters, controlled by Hellenic Army pilots from the 1st Army Aviation Brigade, 1st Infantry Division, First Army, supported by U.S. Marines from the 2nd Air Naval Gunfire Liaison Company, II Marine Expeditionary Force Information Group, launched the assault exercise with precision missile strikes. This was followed by mortar fire from U.S. M252 and Soltam K6 systems. Hellenic Army Leopard 2A6 HEL tanks then advanced under the command of a combined U.S.-Hellenic team, supporting U.S. Humvees armed with M240 and M2A1 machine guns.

Together, coalition mounted infantry forces advanced to clear and hold the objective, paving the way for the 572nd Brigade Engineer Battalion, 86th IBCT (MTN), to breach the area using an M58 Mine-Clearing Line Charge, MICLIC, transported by an M1083 Light Medium Tactical Vehicle. The MICLIC detonated 1,750 pounds of C4 to create a safe path for follow-on forces, producing a powerful shockwave and dense plume of smoke across the battlefield.

As D Company secured the final objective, the day exercise concluded, demonstrating successful multinational synchronization and combat readiness.

“My platoon crushed it,” said Lacasse, “I’ll be a little biased there. I think the overall performance from the first platoon, Delta Company element, and our Greek partners was absolutely amazing. Overcoming some challenges, whether it be language or equipment, we were able to get all that aside and execute the mission flawlessly.”

As the sun set on the final day, U.S. and Hellenic troops executed a second live-fire exercise, using U.S. Humvees and Hellenic tanks under the cover of total darkness. Working together in nighttime conditions added a new level of challenge and helped soldiers improve their coordination, communication, and trust.

“For the Vermont National Guard, and the Army National Guard as a whole, these are things you would never know existed if you didn’t take that step, dip a toe in the water, and go out and see a recruiter,” said Anderson. “I’m super grateful that I enlisted back in 2019, eventually taking up a commission, because it has broadened my horizons and I have stories to tell my children that I never knew I’d be able to tell.”

Demonstrating global deterrence and the U.S. Army’s ability to rapidly deploy U.S.-based combat power in Europe and the Arctic region alongside allies and partners, DEFENDER 25 brings U.S. troops together with forces from 29 Allied and partner nations to build readiness through large-scale combat training from May 11-June 24, 2025.

DEFENDER 25 increases the lethality of the NATO alliance through large-scale tactical training maneuvers and long-range fires, builds unit readiness in a complex joint, multinational environment, and leverages host nation capabilities to increase the U.S. Army’s operational reach. During three large-scale combat training exercises — Swift Response, Immediate Response and Saber Guardian — ally and partner forces integrate and expand multi-domain operations capability, demonstrating combined command and control structures and readiness to respond to crisis and conflict.