Tactical Interoperability through Combined Training: A KRF Story

After days of savage fighting in the mountainous backcountry of South Korea, the two opposing brigades were battered and near exhausted. Two battalion commanders linked up just shy of the military crest in a bold effort to combine their meager forces for one last push into the valley below where an enemy strongpoint awaited. With a cacophony of gunfire to their front and urgent radio chatter coming over the net, they sought to focus and figure out how to survive long enough to snatch victory from the jaws of defeat. They hashed out a plan and settled on attacking immediately while they still had a chance. The remnants of their two formations amounted to little more than an overstrength company, but they had two tanks, and the handful of engineers survived. If friendly artillery could pin down the enemy defenders, it just might be enough to allow them to seize the final objective. As the combined arms task force maneuvered towards the enemy bunker complex, friendly air support flew overhead, providing a much-needed boon to the morale of the infantry-heavy force. Desperately needed friendly 155mm barrages began to rain down in advance of the attacking force. The two battalion commanders shared a glance, realizing they just might survive. Their ability to work together and trust in each other had made the difference.

Despite considerable commonality with the most renowned account of the Korean War, the fierce fighting described above was neither an excerpt from T.R. Fehrenbach’s This Kind of War nor did it occur in the 1950s. It occurred in 2024 during a training event, one of the four combined rotations that occurred at the Korea Combat Training Center (KCTC) this year alone. Notably for this multinational training, only one of the battalions comprised U.S. forces. The rest — the brigade, one of the two battalions, the artillery, the tanks, the engineers, and even the air support — were all from the Republic of Korea Army (ROK-A).

This training was just one of the many challenging and rewarding combined training opportunities that the 3rd Cavalry Regiment (CR) experienced as Korea Rotational Forces (KRF) 14, continuing a commitment of partnership and power projection established by 13 previous U.S. brigade combat teams. As with most of KRF-14’s collective training events, U.S. Army and ROK-A forces worked in close partnership to advance their collective lethality. To do so, they had to address all three components of interoperability — human, procedural, and technical. Although the entire KRF-14 executed significant combined training, one squadron in particular — 2nd Squadron “Sabre” — maximized the opportunity to conduct combined training — which it did extensively with three battalions and the brigade it joined for KCTC. As a result of a purposeful pursuit of combined training, Sabre built readiness and tactical interoperability throughout their rotation.

During National Training Center (NTC) Rotation 23-09, Sabre integrated Task Force (TF) Hero and embarked upon a journey replete with valuable combined training that yielded improved human and procedural interoperability with the ROK-A. TF Hero, a specially trained and selected company-sized task force from the 136th Infantry “Hero” Battalion (ROK-A), included a robust liaison officer (LNO) package with an attached Security Force Assistance Brigade (SFAB) military advisory team (MAT). TF Hero’s LNO package included LTC Sangyup Lee, the 136th IN’s commander who had graduated from the School of Advanced Military Studies. At NTC, he supported TF Hero’s administrative needs while also serving as 3CR’s deputy commanding officer, which allowed him to help prepare the regimental staff for their future cooperation with ROK-A staff officers. One of his company commanders — CPT Lim, who was both an excellent officer and conversant in English — led TF Hero. These leaders and the MAT played a critical command and control (C2) role and enabled TF Hero’s easy integration into Sabre as its fourth maneuver troop. This provided Sabre with indispensable combat power, especially during two successful seizures of large urban complexes. As a result of the MAT pre-NTC live-fire certification, TF Hero conducted an independent troop-sized live-fire exercise (LFX) and then participated in Sabre’s squadron LFX. Sabre’s integration of TF Hero at NTC 23-09 began an effective pairing of two organizations that became symbiotically committed to each other’s success through continual combined training. As lead partner during a combat training center (CTC) rotation, it was relatively easy for Sabre to receive and integrate this ROK-A task force dedicated to being interoperable with the U.S. Army, but training extensively in a host nation as visitors would require additional coordination and support.

Upon arrival to the ROK in early 2024, Sabre welcomed two critical ROK-A attachments. CPT Jae-Oh Lee, a talented ROK-A Special Forces officer, served as the new assistant S-3. He fulfilled multiple essential staff functions (combined training event planner and coordinator, trusted advisor, and expert tactical translator) and was instrumental to the success of all of Sabre’s organizational interactions with the ROK-A. Additionally, the ROK-A supplemented Sabre with 40 Korean Augmentees to [the] U.S. Army (KATUSAs) who performed various military roles from machine gunner to mechanic. Fully integrated into 3CR squadrons, senior KATUSAs served as team leaders and NCOICs as well as trusted translators. With these additional interoperability enhancers, Sabre was better postured to build readiness through continued training with ROK-A units like the 136th IN.

Sabre’s interoperability with the 136th IN flowed from a deliberate effort to build upon their pre-existing NTC relationship. Lasting friendships with this battalion strengthened through a series of informal engagements, typically team-building events and competitions followed by shared dinners. Notably, 50 ROK-A Soldiers joined Sabre as they earned their spurs together. The camaraderie and rapport that these two units built with one another enabled better understanding of each other’s organization and culture. The Hero-Sabre interpersonal connections were human interoperability that proved a vital catalyst for building lethality.

Sabre’s combined training with the 136th IN ranged from individual to the collective level and bolstered procedural interoperability. CPT Lim and dozens of other members of Hero received their Expert Infantryman Badge alongside Sabre troopers after a successful train-up. An early collective training event entailed attaching a Sabre rifle troop to Hero Battalion for a five-day field training exercise (FTX). Throughout the FTX, Sabre’s tactical command post (TAC) co-located with the 136th IN’s tactical operations center (TOC) as both headquarters honed C2 interoperability while learning each other’s tactics, techniques, and procedures (TTPs). Meanwhile, the rifle troop and its platoons experimented with multiple combined task-organization variations.

Later in the rotation, Sabre would integrate a Hero platoon into its platoon LFX. During this day and night LFX, a ROK-A squad attached to most of the executing Sabre platoons, and in turn, Sabre attached a weapons squad to the 136th IN platoon for its execution of the same scenario. This success went beyond purposeful relationship building and sharing of TTPs; effective rehearsals and the dedicated use of KATUSAs as tactical interpreters proved instrumental. By Sabre’s second LFX series with Hero, both units had advanced their procedural interoperability and established the trust to combine at a lower echelon for the live fire. This bred confidence and camaraderie as both units learned how to better operate and train together. Beyond building tactical acumen, the partnership with Hero paid dividends for Sabre by establishing connections, as well as a reputation, and goodwill that assisted the squadron in future combined operations with other ROK-A units.

As an experienced and interoperable KRF formation, Sabre coached the 137th Infantry Battalion (ROK-A) through a live-fire training progression to prepare it for an upcoming NTC rotation, where it would train with 1-2 Stryker Brigade Combat Team, which would replace 3CR as the KRF. In the past, an SFAB MAT had entirely fulfilled this training and advisory role; however, Sabre possessed all of the requisite skill sets to build the lethality and interoperability that the 137th IN needed for NTC. The training began with weapons qualifications and squad situational training (STX) lanes and progressed to a battalion task force-sized LFX. Upon completion of STX lanes, Sabre facilitated the 137th IN’s dry-, blank- and live-iteration maneuver lanes. Sabre also fostered concurrent training with the 137th IN and enhanced their soldiers’ understanding of how the U.S. Army fights at NTC. The advisory experience benefited the squadron’s leaders by exposing them to the type of advisory operations normally reserved for an SFAB organization. This proved to be a unique opportunity to coach and mentor ROK-A Soldiers and continue to work through language barriers. This experience became even more valuable for Sabre when it later worked under the direct command of a ROK-A brigade.

Sabre put both its lethality and interoperability to the test during an 11-day brigade-sized force-on-force FTX at KCTC. Under the tactical control of the 7th Brigade, 6th Infantry Division (ROK-A) for KCTC 24-06, Sabre fought within the ROK-A brigade as one of its subordinate infantry battalions. Sabre’s second combined CTC rotation featured a role reversal in which it was now the subordinate partner for rigorous combined training. Not only did the daunting terrain and climate of KCTC challenge the entire squadron, the immersive and demanding training also provided extensive leader development and fostered the necessary small-unit cohesion to prevail in LSCO. This tremendous developmental opportunity provided the most valuable and highest quality training that Sabre conducted during KRF-14.

Beyond the training in execution, KCTC 24-06 also built readiness for the squadron leadership through repeated iterations of combined planning. Early on, the 7th Brigade hosted Sabre for two coordination meetings that refined the KCTC operation order (OPORD) and furthered the units’ relationship. The growing interoperability between the 7th Brigade and Sabre blossomed during two multi-day recons of KCTC. These doubled as collaborative planning conferences and allowed leaders to conduct terrain walks of the training grounds. The 7th Brigade commander also gave a doctrinal leader professional development (LPD) session on North Korean People’s Army/OPORD tactics. This proved to be one of the most valuable touchpoints while preparing for KCTC because it gave Sabre’s commanders and staff insight into an enemy that few, if any, had experienced before. As a result of the deliberate effort to facilitate braided planning, Sabre went into KCTC 24-06 well postured to serve under 7th Brigade’s command — provided that the squadron could facilitate the requisite interoperability in execution.

During KCTC 24-06, Sabre achieved interoperability within the 7th Brigade and alongside its subordinate battalions through two primary means: frequent face-to-face commander meetings and command post LNO packages. Throughout the entire operation, the commanders of both 7th Brigade and Sabre frequented one another’s command posts to synchronize operations and ensure shared visualization. Sabre maintained a common operating picture with the brigade and exchanged LNO packages with both brigade headquarters and its fires battalion. Due to the ROK-A using different systems and methods to track ground and air forces, responsiveness varied between the different units in the combined task force. However, technical rehearsals and LNO utilization soon decreased the mission-processing time by 75 percent. The ROK-A provided an Army Tactical Command Information System (ATCIS) with trained operators (similar to the Joint Battle Command-Platform [JBC-P]) and a voice over internet protocol (VOIP) phone for Sabre’s command post. Sabre provided an LNO package with radios and a JBC-P to the brigade CP. Overall, this C2 architecture worked well; strengths in each system overcame weaknesses in the other to enable a common operating picture. These collective efforts empowered the 7th Brigade and Sabre through expedient reception and delivery of information, resulting in deconflicted maneuver and effective indirect fires across the battlespace. Despite all the improvements with combined C2 for battalions and above, the language barrier still posed a considerable interoperability challenge at the frontlines.

Sabre had to make a concerted effort to enable its troops to communicate with adjacent ROK-A units and identify friend versus foe. Since the efforts to establish technical interoperability for communications faltered throughout much of our KRF-14 rotation, Sabre devised a plan for each troop to implement dedicated guide packages, which consisted of a fire team and an English-speaking KATUSA. Each team would meet the adjacent ROK-A companies at a designated contact point and facilitate critical reporting up to both parent headquarters. With 3CR allocating additional KATUSAs for KCTC, Sabre was able to place more into platoons to serve as interpreters. These guide packages facilitated forward passage of lines and, in a notable instance, became how a Sabre troop assumed command of a ROK-A company’s remnants. Pairing the right Korean and English speakers together ensured that Sabre and the 7th Brigade could coordinate on-the-spot adjustments to the plan. The struggle with positive identification of the opposing force (OPFOR) stemmed from a limited ability to mark all friendly forces, insufficient coordination during hours of darkness, and the similarity between OPFOR and ROK-A uniforms. To prevent fratricide, Sabre’s troops employed restrictive rules of engagement and cleared ground repeatedly for both direct and indirect fires. As a result, Sabre mitigated the widespread concern of U.S.-ROK-A fratricide. Despite the high degree of interoperability that Sabre displayed during its multinational combined arms training at KCTC, the squadron achieved its greatest interoperability during the subsequent 3CR combined arms live-fire exercise (CALFEX).

With a tank platoon from the 81st Tank Battalion (ROK-A) attached to each troop, the CALFEX allowed Sabre to bring together all three elements of interoperability. In a bit of irony, the first and final combined training events that Sabre conducted in the ROK occurred with the 81st Tank. Early in the KRF-14 rotation, Sabre supported the 81st Tank’s CALFEX with an enabler package that consisted of the squadron’s small unmanned aerial system assets, an S-2 node, a fire support team, and two KATUSAs to facilitate the sensor-to-shooter process with the 81st Tank’s mortars. The early relationship building fostered the human and procedural interoperability that later combined with technical interoperability. During the CALFEX, Sabre overcame the challenge to communications interoperability with special equipment provided by our higher headquarters. This enabled our command post and troops to communicate directly with our attached tanks. This technical interoperability proved invaluable in enabling lethal combined arms maneuver as K1 tanks provided a booming support by fire in close proximity to advancing Sabre infantry who were communicating with them. Nevertheless, for all the interoperable strides that Sabre had made, certain basic tenets still held. During the planning phase, the most valuable way to communicate the plan remained through in-person meetings and rehearsals. As Sabre’s combined collective training culminated with the CALFEX, the squadron had brought all aspects of interoperability together.

Conclusion

Sabre Squadron’s nine-month KRF experience was an invaluable builder of readiness and tactical interoperability. Building upon the relationships that began at NTC 23-09, the bonds between Hero and Sabre grew only stronger with team building and proficiency gained during combined collective training events. Sabre continued to forge the cycle of interoperability for future KRFs by coaching the 137th IN through a platoon and company LFX train-up to prepare them for their combined NTC rotation with KRF-15. Invaluable squadron-level collective training occurred during our KCTC rotation under the command of a ROK-A brigade. Success at KCTC required Sabre to employ all the interoperability TTPs it had already learned and innovate to establish new ones. As a result, the squadron benefited from a world-class training experience and its second combined CTC rotation in less than a year. Sabre’s troops then executed a combined CALFEX that allowed them to maneuver with an embedded ROK-A tank platoon. Throughout KRF-14, 2/3 CR immensely benefited from an intensive combined training glidepath. While integrating and training alongside ROK-A allies from the squad to the squadron level, Sabre built tactical interoperability and lethality — all while helping to strengthen a critical seven-decades-old alliance.

LTC Josh Silver is an Infantry officer and the former commander of 2nd Squadron “Sabre,” 3rd Cavalry Regiment (CR). Prior to command, he served as an observer coach/trainer (OC/T) and later the Command and Control (C2) Chief in the Mission Command Training Program (MCTP). During that time, he helped Afghan refugees come to the United States during Operation Allies Refuge and Operation Allies Welcome. In 2020, he conducted a no-notice deployment with 1st Brigade, 82nd Airborne Division to the U.S. Central Command (CENTCOM) area of responsibility (AOR). He also taught American and Military History at the U.S. Military Academy at West Point, NY. LTC Silver has two combat deployments to Iraq and another to Afghanistan. His next assignment will be to the National Capital Region.

MAJ Matthew Dixon is an Infantry officer and the former executive officer (XO) of 2/3 CR. He previously served as a company commander and S-3 in the 3rd Security Force Assistance Brigade where he deployed to CENTCOM in support of Operation Spartan Shield. In 2019, he deployed with C Company, 1st Battalion, 87th Infantry Regiment, 1st Brigade Combat Team, 10th Mountain Division, in support of Operation Freedom Sentinel. He also served at the Army Physical Fitness School and has two combat deployments in support of Operation Enduring Freedom and Operation Freedom’s Sentinel.

CPT Brandon Latham is a Field Artillery officer and the current fire support officer of 2/3 CR. He previously served in 2nd Armored Brigade Combat Team, 1st Armored Division, where he deployed on a CENTCOM rotation 2020 in support of Operation Spartan Shield.

CPT Zachary Watters is a Military Intelligence officer and the former S-2 of 2/3 CR. He previously served in the 1st Combat Aviation Brigade where he deployed on a 2021 U.S. European Command rotation in support of Operation Atlantic Resolve. He is currently the acting S-3 of Sabre Squadron.

This article appears in the Summer 2025 issue of Infantry. Read more articles from the professional bulletin of the U.S. Army Infantry at https://www.benning.army.mil/Infantry/Magazine/ or https://www.lineofdeparture.army.mil/Journals/Infantry/.

As with all Infantry articles, the views herein are those of the authors and not necessarily those of the Department of Defense or any element of it.