‌Subterranean Role 1 Medical Facility Experiment for Large Scale LSCO

Lessons Learned from One of the First Medical Company (Area Support) to Conduct Subterranean Role 1 Medical Operations

By 1LT Leoniel O. Rodriguez Rosas, CPT Ryan C. Brown, and 1SG Sakeena Lites

Article published on: March 1, 2026 in the 2026 E-Edition of Pulse of Army Medicine

Read Time: < 32 mins

The growing complexity of modern warfare in recent global conflicts necessitates a reevaluation of U.S. Army training as it transitions into Large-Scale Combat Operations (LSCO) and Multi-Domain Operations (MDO). The increasing use of drones and precision artillery on the modern battlefield poses significant threats to U.S. medical assets, highlighting the necessity for innovative solutions to protect medical assets and enhance casualty care in future conflicts. In modern conflicts like the Russia-Ukraine War and the Hamas-Israel Conflict, the most casualty-producing type of weapon is artillery, which is purportedly responsible for nearly 80 percent of the total casualties (Suciu, 2024). The Ukraine-Russian War also saw the evolution of a new danger through the employment of drones in the combat environment. In 2025, drones dominated the battlefield, inflicting over 70 percent of total casualties (Santora, et al., 2025). Countries involved in these conflicts, like Ukraine and Israel, have identified the use of subterranean facilities to avoid the repercussions of artillery, provide shelter to their refugees, and establish a haven for Medical Treatment Facilities (MTFs). The lessons learned from modern conflict demand that U.S. military MTFs operate under robust cover and concealment, like subterranean and underground facilities, to minimize casualties and maximize mission effectiveness.

Incorporating subterranean Role 1 configurations in Army Medical Doctrine will enable Commanders to provide continuity of Role 1 capabilities to the Warfighter in a concealed and covered environment, reducing mortality across the battlefield. The 550TH Medical Company Area Support (MCAS) experimented with a subterranean Role 1 configuration to assist in the exploration of standardizing subterranean medical operations. The goal of sharing that experience and lessons learned is to contribute to the existing body of knowledge that may impact doctrinal reform.

Historical Context of Medical Subterranean Operations

As the U.S. prepares for potential conflicts with near-peer adversaries, using innovative operational strategies, such as subterranean operations, is essential to counter air domain advantages. Analyzing historical subterranean engagements may help integrate these strategies into future medical operations.

The last Large-Scale Combat in which the U.S. engaged its troops was World War II. Although the war ended over 80 years ago, it is still a primary source for current military studies, which abstract lessons learned from LSCO and apply them to modern combat.

Over the course of six years, World War II claimed the lives of approximately 15 million military personnel and more than 38 million civilians.3Artillery and mortar fire produced the highest casualties of U.S. military personnel during the war, including approximately 69 percent in the Mediterranean, 64 percent in Europe, and 47 percent in the Pacific.4Axis forces also carried out constant air raids aimed at key infrastructure, logistics hubs, and medical facilities. The complexity and changing environment of large-scale combat operations forced Allied medical units to adapt by moving into subterranean facilities, which helped protect and conceal medical operations from enemy forces.

Yugoslavia, for example, developed a medical system that effectively employed Partisan medical units by adapting their facilities based on the environment.5Dr. Lindsay Rogers’ records of his time across the Partisan hospital network system describe multiple types of subterranean facilities categorized into two types: underground bunkers and excavated shelters.

Underground bunkers consisted of facilities built mainly in proximity to Yugoslav hospitals. Their primary function was to conceal and protect patients and supplies in the event of an enemy attack. The construction of underground bunkers relied on deliberate planning, preparation, and execution to include crew employment, ventilation and drainage systems, shoring construction, and natural concealment to preserve secrecy. A construction crew cut the shoring material miles away from the subterranean location and transported it only at night to reduce detection by Axis forces. For the most part, the bunkers served as holding areas where wounded personnel could remain concealed for several weeks if necessary.

In contrast, excavated shelters were medical sites built into natural caverns or dug into forested terrain. They were often put together with fewer resources than underground bunkers but were still deliberately planned. The caverns served as improvised emergency operating rooms and patient-care shelters.6Units that required immediate concealment with minimal time to continue medical operations often employed this type of improvised facility.

Forest excavations varied depending on the terrain analysis and mission variables; however, they mostly consisted of partially dug facilities camouflaged with the natural environment. The most critical factors in effectively employing this type of medical facility were tracks concealment, noise discipline, and camouflage of the facility according to the environment. Partisan units used this type of configuration to cover and conceal the facility from enemy forces, which enabled surgical and patient holding capabilities near the front lines.7None of the camouflaged medical facilities in the forest were discovered by opposing forces.

In modern conflicts, countries like Israel and Ukraine use subterranean facilities as a haven for medical operations. The Russia-Ukraine war is generally considered Europe’s first Large-Scale conflict since World War II.8Total deaths for Russian military personnel are rising daily; however, accurate estimates are impossible due to the ongoing conflict. In 2023, Russia officially estimated its death toll at 250,000 while Ukraine’s death toll ranged between 60,000 and 100,000. 9As for injured personnel, Russia estimated 700,000 casualties in 2025 while Ukraine estimated between 240,000 and 300,000 casualties.10Although modern LSCO continues to evolve with the introduction of drone attacks, the Russia-Ukraine war demonstrated that artillery and air raids continue to be the most casualty-producing capabilities in Large-Scale Combat.

Furthermore, the Ukraine-Russian war bears many similarities with World War II, as healthcare facilities are consistently one of the primary targets in the conflict. The World Health Organization recorded 2,477 attacks on Ukraine’s medical facilities between 2022 and 2025. Consequently, Ukraine used subterranean operations for surgical teams to reduce mortality rates amid heavy casualties.11In 2024, Ukraine established its first underground hospital for its Armed Forces to begin operations.12The medical facilities are constructed of steel and well-equipped with ventilation, power supply, and water access. (See Figure 1) Their capabilities include an operating room and advanced lifesaving equipment, capable of providing daily treatment to over 100 casualties. Ukraine’s Minister of Defense, Rustem Umierov, declares these medical stabilization points critical assets to their Warfighters because of their proximity to the front lines. The medical facility’s protection and concealment from Russian forces allows Ukrainian forces to provide rapid surgery and immediate lifesaving measures near the point of injury, increasing casualty survivability rates on the battlefield.

In both World War II and the Ukraine-Russian War, the most prominent characteristic of subterranean medical facilities is the proximity to the Warfighters to enable life preservation. As Role 1 medical facilities are closest to the front lines, the U.S. Army must use historical lessons learned to reshape and continue its safe employment in future LSCO.

Role 1 Medical Facility

The Role 1 medical facility, also known as the medical platoon and the Battalion Aid Station (BAS), is the “forward-most medically staffed” medical facility, capable of providing health service support (HSS) to the Warfighter by conducting medical treatment and evacuation to higher levels of care.13Its proximity to the forward line of troops (FLOT) is 5-7 kilometers (3.1 to 4.3 miles), or two terrain features, making this element vital to preserving life and returning warfighters to the front lines. There are two types of units capable of providing Role 1 capabilities: the Medical Platoon and the Medical Treatment Squads from a Brigade Support Company (BSMC) or an MCAS, which are the Role 2 level of care.

The Medical Platoon is organic to the maneuver battalion with slight differences in capabilities and resources between the infantry, armored, and Stryker Brigade Combat Teams (BCT). It provides Role 1 capabilities to its maneuver battalion by establishing a BAS capable of providing medical treatment, medical evacuation (MEDEVAC), and medical command and control (MED C2).

Similarly, the Medical Treatment Squads are organic to both types of Role 2 MTFs and can provide Role 1 capabilities for limited periods of time. Their difference lies in the supported unit and the periods of time during which they can operate. While the BAS provides Role 1 capabilities to its organic battalion, both the BSMC and the MCAS provide Role 1 capabilities on an area basis, which significantly differs from each other.

The BSMC usually employs its Medical Treatment Squad in support of its organic Brigade’s maneuver battalions. Its primary function is to augment another Role 1 within the Brigade or to establish a Role 1 MTF that can decompress casualties from the maneuver Battalion Aid Stations. The BSMC Role 1 consists of one Medical Treatment Squad capable of splitting into two teams, which can only operate separately from each other for limited periods of time.

Contrary to the BSMC, the MCAS has two Medical Treatment Squads capable of operating independently from the parent unit as a Role 1 MTF, allowing both squads the ability to further split into two teams per squad.14

The MCAS Medical Treatment Squads have the same capabilities as the BSMC. The main difference between them is that the MCAS employs its assets to units without organic Role 1s or to units requesting additional medical assets. During the subterranean Role 1 MTF configuration, a Medical Treatment Squad from the 550TH MCAS tested the operation.

Forging the Subterranean Role 1 Configuration

The 550TH MCAS, part of the 261ST Medical Multifunctional Battalion and 15 the 44TH Medical Brigade, experimented with the subterranean Role 1 configuration from 14 to 16 January 2025. Highly influenced by Dr. Lindsay Roger’s observations and by Ukraine’s medical stabilization points, the 550TH MCAS built a subterranean Role 1 concealed with the environment and proximal to the Warfighter. By U.S. Army standards, the configuration is considered a sophisticated Category 1 subterranean facility. The unit organized the execution of the subterranean configuration into three phases: excavation, structural construction, and medical capability development.

Excavating the prescribed dimensions required external support from the 618TH Engineer Support Company (ESC). 618TH ESC completed the excavation in approximately 4 hours. Although the unit could excavate the site using standard-issued equipment, such as entrenching tools and shovels, the engineer support significantly reduced fully operational capable (FOC) times by approximately 83 percent, making engineer support a vital asset to expedite the establishment of Role 1 subterranean operations.

Constructing the subterranean structure consisted of five steps: building the foundation, framing the entrance, framing the exit, and framing the left and right-side walls. The building operation lasted approximately 14 hours with only six Soldiers working at a time. Once completed, the facility was able to provide MED C2, medical treatment, and MEDEVAC capabilities.

Upon completion of the subterranean structure, the Role 1 personnel occupied the treatment facility. Similar to establishing a traditional Role 1 (tented or hard stand), the subterranean Role 1 provided two Advanced Trauma Life Support (ATLS) beds. The triage area, which is the area in which medical personnel categorize patients based on severity of injury or illness, was located under the camouflage netting either at the ambulance or on the ground with a medic to ensure continuous masking of heat signature and concealment from enemy drones and aircraft. Based on ATLS bed availability, the PL would inform the ambulance Con to transport patients from the triage area to the facility. Upon completion of patient care, litter bearers moved the patient to the holding area awaiting evacuation either at the exit of the facility or directly to the ambulance, depending on ambulance availability. Figure 3 outlines the subterranean Role 1 configuration for medical treatment.

The PL and PSG emplaced their evacuation assets based on mission variables, a minimum distance of 100 meters from the facility. When emplacing evacuation teams, leaders dispersed and camouflaged the ambulances to reduce enemy detection of both the subterranean facility and the ambulances. Evacuation teams were prepositioned with their ambulances facing the direction of travel, ensuring the selected area was accessible to known improved or unimproved roads. Additionally, the evacuation teams ensured internal communications through their Single Channel Ground and Airborne Radio Systems (SINCGARS) and external communications through the supported unit’s communication plan. Camouflage netting was crucial in reducing the likelihood of enemy detection. When transporting patients to and from the medical facility, litter bearers used a modified clover leaf method, or the dog leg method, to avoid building a natural route, thus avoiding detection of the subterranean facility or the concealed ambulance.

Lessons Learned

Multiple challenges and constraints arose during the execution of the subterranean Role 1 MTF configuration. The 550TH MCAS consolidated them into lessons learned and presented them through the lens of various mission variables (METT-TC), conformity to the Army Health System (AHS) principles, and limitations in practice to aid further subterranean engagements for medical units across the U.S Army.

Mission Variables

On the battlefield, leaders are constantly receiving new information throughout every phase of the operation, making mission variables an ongoing process that helps them analyze the constantly shifting complexities of the operational environment.16The U.S. Army uses the mission variables of mission, enemy, terrain and weather, troops and support available, time available, and civil considerations (METT-TC), all of which are critical to effectively employing a Role 1 medical facility under subterranean conditions.

Mission

The mission type and its development will always dictate the execution and emplacement of the subterranean Role 1. Commanders must identify decision points throughout the phases of the operation that will help decide when the unit must transition to subterranean operations.

Typically, units can employ this Role 1 configuration during defensive operations and when static at a location for long periods of time. Hence, units with Role 1 capabilities must master the fundamentals, especially troop leading procedures (TLPs), to streamline the employment of the Role 1 configuration. Additionally, conducting realistic training will allow medical units and Commanders to become proficient at TLPs while including decisive points to conduct subterranean operations, reinforcing critical thinking among Commanders and medical leaders.

Enemy

The growing use of drones and precision artillery in recent conflicts raises concerns when preparing for future conflicts, making enemy considerations and capabilities important factors when conducting Role 1 subterranean operations. Near-peer enemies might have the capability to identify friendly forces through surveillance drones, satellite imagery, and electromagnetic emissions. This capability will enable them to suppress friendly efforts through artillery, mortars, drone attacks, mounted and dismounted patrols, as well as Chemical, Biological, Radiological, and Nuclear (CBRN) capabilities. Therefore, avoiding enemy detection is critical to the survivability of the subterranean Role 1 MTF personnel. In response to enemy considerations, there are three vital suggestions to mitigate enemy detection: noise and light discipline, the use of camouflage, and training under CBRN conditions.

First, noise and light discipline must become second nature for personnel executing subterranean operations. Units can maintain noise and light discipline through training and enforcing strict noise and light protocols. Light discipline protocols include limiting the use of red and green lights to the inside of the MTF and using Night Vision Devices (NVDs) or Night Vision Goggles (NVGs) outside of the MTF. Moreover, using noiseless generators, covered with camouflage nets that disperse electromagnetic signature, and exercising blackout protocols will further reduce the probability of enemy detection.

Secondly, camouflage around the area of operations is essential to mitigate exposure to enemy capabilities. Units must consistently train on the camouflage techniques of personnel and equipment. The entrances of the subterranean facility and all rolling stock must be under a camouflage net capable of dispersing electromagnetic signature to evade thermal imaging detection.

Finally, as CBRN threats are a projection for future LSCO, medical units must train under CBRN conditions including operating under different levels of Mission Oriented Protective Posture (MOPP) gear, training all personnel on patient and personal decontamination, and learning the NBC filtration system in their assigned ambulances.

Becoming familiar with these techniques will reduce the probability of exposing the subterranean Role 1 personnel to enemy surveillance capabilities.

Terrain and Weather

Large-Scale Combat will demand adaptability from all U.S. personnel, which requires all leaders to assess the terrain constantly and determine how it will affect subterranean operations. For the 550TH MCAS team, the terrain in which they executed the configuration was sandy and loose, which challenged the 618TH ESC and 550TH MCAS during the excavation and construction phases. During the excavation and construction of the structure, the walls continued to collapse on both teams. To ensure the facility complied with the prescribed measurements, the building team had to regularly shift focus from building to shoveling the collapsed sand out of the site. These external factors doubled the unit’s estimated FOC times.

To mitigate this challenge in subterranean operations, leaders must analyze the terrain meticulously and plan accordingly to avoid delays in FOC times. In the case of the 550TH MCAS, a simple solution would have been for the engineers to excavate deeper and broader to ensure enough space for the construction. The engineers could then have backfilled the space upon completion of the construction.

Furthermore, cover and concealment are both key terrain considerations that unit Commanders must understand when employing a subterranean Role 1. TC 21-75 defines cover as a structure, natural or manufactured, strong enough to sustain bullets, explosive rounds, flame, nuclear effects, biological and chemical agents, and enemy observation.17In contrast, concealment is anything, natural or manufactured, that protects friendly forces from enemy detection.18When constructing the subterranean Role 1 MTF, the 550TH MCAS focused on providing concealment from the enemy with limited cover. Although the structure could withstand the detonation of a grenade carried by a drone, it would not endure near peer precision artillery or CBRN capabilities.

Therefore, when employing the subterranean Role 1 configuration, Commanders should view it as a facility concealed from enemy detection, not as one that is protected or shielded from enemy capabilities.

If Commanders prioritize cover from enemy capabilities, they should consider occupying a Category 2 or 3 underground facility that provides such protection. However, if the Operational Environment lacks Category 2 or 3 underground facilities, Commanders should consider incorporating elements from Ukraine’s medical stabilization points by enhancing the subterranean Role 1 configuration with materials capable of withstanding enemy capabilities, such as structural reinforced concrete, a CBRN-protected ventilation and water system, and more extensive excavations.

Finally, climatic considerations also have substantial effects on the construction and employment of subterranean operations. A poorly built structure can lead to flooding the facility, hindering patient flow, and potentially damaging medical equipment. The 550TH MCAS identified two suggestion points that can reduce potential risks to the subterranean facility.

First, during the construction, units must build a French drainage system (diagram) in the foundation of the facility to avoid flooding. Second, the unit seal the entrances of the facility and waterproof supplies and sensitive equipment to avoid potential damage to both the facility and the equipment.

Troops and Support Available

Considering troops and support available for the subterranean operations ensured mission success for the 550TH MCAS. Without support from the engineers, the unit would have completed the excavation in approximately 24 continuous hours instead of the 4 hours it actually took. Engineer support is critical for this type of Role 1 configuration. Medical units must include engineer support during the planning phase to reduce FOC times. In addition, units can expand engineer support by requesting a building team that can construct the foundation and structure of the facility, ensuring a rapid deployment of the configuration and allowing the Role 1 to focus solely on patient care.

Time Available

Time, often the first component of leader analysis, is one of the most precious resources during the planning, preparation, and execution of any military operation.19During the subterranean Role 2 experiment, the 550TH MCAS identified that time is a significant planning consideration during patient evacuation operations.

The projected capabilities of future adversaries pose substantial threats to all medical platforms. The U.S. Army’s current unarmored ground MEDEVAC assets are highly susceptible to drone strikes and artillery capabilities. The 550TH MCAS suggests conducting all MEDEVAC operations from the subterranean Role 1 at night, increasing protection of the Role 1 and its vital ground MEDEVAC assets, which significantly reduces the time available to evacuate patients to approximately 8-10 hours per day. This planning consideration implies that units will have patients for longer periods, increasing prolonged field care times. To reduce patient stress on the Role 1, units must maximize the time available to evacuate patients.

Civil Considerations

In mission variables, civil considerations are simplified into areas, structure, capabilities, organizations, people, and events (ASCOPE).20However, to maintain the Role 1 configuration applicable to multiple Combatant Commands, the focus will be capabilities and organizations.

Depending on the country and prior approval, the deployed host nation could have medical capabilities in proximity to

U.S. forces, able to decompress patients. The 550TH MCAS identified gaps in how the unit would communicate with host nation medical facilities to divert patients to their area of operation if they are only using organic communication assets. To mitigate this gap, units must maintain communication with higher headquarters, specifically

with the medical regulating liaison that could facilitate communication between host nation medical facilities and the Subterranean Role 1.

Army Health System Principles

Having considered several decisive mission variables, analyzing the AHS principles provides medical planners with an understanding of the subterranean configuration from a medical doctrine perspective that may assist during the planning phase of the concept of medical support

for their maneuver elements. The AHS principles are the foundation of field environment healthcare planning and execution.21The AHS principles consist of conformity, proximity, flexibility, mobility, continuity, and control. The 550TH MCAS assessed that the subterranean Role 1 MTF configuration conforms to five of the six AHS principles, with mobility being the exception.

The mobility of AHS assets ensures that medical units remain within supporting distance of their maneuvering elements. Although the Role 1 personnel and equipment remain highly mobile, the subterranean structure is not mobile. For safety considerations, units should not remove built-in structures when displacing or retrograding the Role 1 MTF to a new location. To increase mobility, units should pre-build the shoring in parts during the preparations phase. Upon occupying the site, units can then assemble the shoring for a rapid deployment of the subterranean Role 1. Working with the Army Futures Command to develop a product that is light and strong enough to serve as a shoring system for the subterranean Role 1 would eliminate the established building phase. The product must include an easily deployable and reusable assembly with a drainage system in its foundation.

Limitations

Conducting the subterranean MTF experiment was not without its limitations. Military leaders must consider the availability of subterranean training resources, the restricted available space within the facility, and the health risks and threats to both medical personnel and patients associated with subterranean operations when employing this configuration.

Subterranean Training Resources

As the Army transitions into Large-Scale Combat and the necessity to conduct subterranean operations becomes a priority, the significant lack of subterranean training areas and resources becomes a constraint to train units effectively. Leaders may overcome this resource constraint at both the strategic and tactical levels. At the strategic level, senior leaders, both military and civilian, must recognize the necessity to train under subterranean conditions and facilitate subterranean training facilities in central military installations to train and increase training realism effectively. The training facilities can be unused shipping containers, above- ground rooms, buildings that simulate subterranean conditions, or actual underground facilities.

At the tactical level, units can improvise with available resources as was the case for the 550TH MCAS. The unit conducted its subterranean preparation in a room inside the Company area. The room was marked with tape to outline the prescribed dimensions, establishing the Role 1 within the parameters and allowing medical scenarios to be conducted inside the space.

This facilitated training within the unit area using minimal resources while familiarizing the Soldiers with the configuration. Other recommended methods are using a container to simulate subterranean conditions or collaborating with the installation’s Range Control to establish a permanent subterranean structure.

Confined Spaces and Low Oxygen Level

Another limitation associated with the Role 1 subterranean configuration was how confined spaces and narrow passages restricted the use of medical equipment, litter movement, and medical personnel access. Therefore, the unit recommends transitioning from bulky, outdated medical equipment to portable life support equipment such as battery-powered compact ventilators, oxygen concentrators, wearable vital signs monitors, and modular surgical kits.

Moreover, poor ventilation hinders patient care for both the medical personnel and the patient due to low oxygen levels, depending on the subterranean facility category. To mitigate hazards associated with low oxygen levels,

units should consider installing a ventilation system for the subterranean facility.

Health Risks and Threats

Health risks and threats associated with subterranean operations are no different from those sustained in any other Operational Environment. However, ATP 4-02.4 outlines common conditions associated with subterranean operations that can increase the number of casualties operating under subterranean conditions.22These include operating in confined spaces and under limited visibility, fear of being trapped or buried alive, lack of cover or concealment, and disorientation in both time and space. To minimize these risks, units must train under subterranean conditions to increase Soldier adaptation and confidence in this type of environment.

Driving Change Through Innovative Operational Strategies

Incorporating subterranean Role 1 configurations in Army Medical Doctrine will enable Commanders to provide continuous Echelon I of medical treatment in a concealed and covered environment from drones and artillery, reducing the mortality of critical medical assets across the battlefield. The 550TH Medical Company (Area Support) subterranean Role 1 MTF experiment provided lessons learned and experiences for U.S. Army leaders to further refine, analyze, and train under this critical capability. It highlighted its potential to enhance Tactical Combat Casualty Care in Large-Scale Combat Operations and Multi-Domain Operations. By implementing lessons learned from historical medical subterranean operations and the 550TH MCAS subterranean Role 1 configuration, the U.S. Army can develop innovative operational strategies to counter air domain advantages and protect medical assets during offensive and defensive operations. Although this subterranean configuration requires further development, the collected data is essential to continue training, modernizing and transforming this vital capability in future medical operations, providing leaders with the training and expertise necessary to thrive in the complexity of Large-Scale Combat. Ultimately, continuing to experiment with different concepts and subterranean Role 1 configurations will contribute to the advancement of operational medicine in possible near peer conflicts that will eventually create a demand for doctrinal change.

Notes

1 Suciu, Peter. “The Ukraine War Is One Massive Artillery Fight.” The National Interest, June 21, 2024.

2 Santora, Marc, Lara Jakes, Andrew E. Kramer, Marco Hernandez, and Liubov Sholudko. “A Thousand Snipers in the Sky: The New War in Ukraine.” New York Times, March 3, 2025.

3 Defense Manpower Data Center. Conflict Casualties: World War II. n.d. https://dcas.dmdc.osd.mil/dcas/app/conflictCasualties/ww2.

4 Oganga, Jeff. “What Weapon Killed the Most People in World War 2?” World Atlas. May 4, 2024. https:// www.worldatlas.com/world-wars/what-weapon-killed-the-most-people-in-world- war-2.html.

5 Colesar, M. T. Study of Yugoslav Guerrilla Forces of WWII to Inform Modern U.S. Army Strategy During a Near-Peer Military Conflict. Bethesda, MD: Uniformed Services University of the Health Sciences, 2019.

6 Dragic, D. Partisans Hospitals in Yugoslavia 1941–1945. Meditsnia Publishing House, 1964.

7 Rogers, Lindsay. Guerrilla Surgeon. Pickle Partners Publishing, 2015.

8 Walmsley, K. R., and A. King. “Through a Glass Clearly: An Improved Definition of LSCO.” Military Review Online Exclusive, 2023.

9 Cooper, Helene, Thomas Gibbons-Neff, Eric Schmitt, and Julian E. Barnes. “Troop Deaths and Injuries in Ukraine War Near 500,000, U.S. Officials Say.” The New York Times, 2023.

10 Sauer, Pjotr. “One Million and Counting: Russian Casualties Hit Milestone in Ukraine War.” The Guardian, June 22, 2025. https://www.theguardian.com/world/ng-interactive/2025/jun/22/one-million-and-counting-russian-casualties-hit-milestone-in-ukraine-war.

11 World Health Organization. Number of Attacks on Health Care in Ukraine Monthly 2022– 2025. Statista, 2025. https://www.statista.com/statistics/1302077/attacks-on-health-care-ukraine/.

12 Sapwood, Olivia. “The First Underground Hospital for the Armed Forces of Ukraine Is Put into Operations.” Militarnyi, September 3, 2024. https://militarnyi.com/en/news/the-first-underground-hospital-for-the-armed-forces-of-ukraine-is-put-into-operation/.

13 Headquarters, Department of the Army. Medical Platoon. Army Techniques Publication No. 4-02.4. (Washington, DC: Department of the Army, May 12, 2021), 1-1.

14 Headquarters, Department of the Army. The Medical Company (Role 2). Army Techniques Publication No. 4-02.4. Washington, DC: Department of the Army, November 2022.

15 Headquarters, Department of the Army. Subterranean Operations. Army Techniques Publication No. 3-21.51. Washington, DC: Department of the Army, November 1, 2019.

16 Headquarters, Department of the Army. Infantry Rifle Platoon and Squad. Army Techniques Publication No. 3-21.8. (Washington, DC: Headquarters, Department of the Army, 2024), 2-21.

17 Headquarters, Department of the Army. The Warrior Ethos and Soldier Combat Skills. Technical Manual No. 21-75. (Washington, DC: Headquarters, Department of the Army, 2013), 5-2.

18 Headquarters, Department of the Army. The Warrior Ethos and Soldier Combat Skills, 5-3.

19 Headquarters, Department of the Army. Infantry Rifle Platoon and Squad, 2-27.

20 Headquarters, Department of the Army. Infantry Rifle Platoon and Squad, 2-28.

21 Headquarters, Department of the Army. Army Health System. Army Techniques Publication

No. 4-02. Washington, DC: Department of the Army, November 2020.

22 Headquarters, Department of the Army. Medical Platoon, 3-55.