Large-Scale Combat Operations Symposium – Detention Operations in LSCOs: a U.S. Military Perspective


| Jun 2, 2023


Editor’s note: The following post highlights a subject addressed during an expert workshop that the Lieber Institute co-convened alongside Harvard Law School’s Program on International Law and Armed Conflict and the International Committee of the Red Cross, focusing on some of the legal issues arising in large-scale combat operations. For a general introduction to this symposium, see Winston Williams and Jennifer Maddocks’ introductory post.

Conflict inevitably involves a requirement to detain. In large-scale combat operations (LSCO) there are likely to be large numbers of persons detained both on land and at sea. These individuals could include enemy soldiers, civilians, or other actors whose status may not be evident. This post explores some of the challenges that a detaining authority is likely to face during LSCOs. It focuses on the roles and responsibilities of the detaining power both in preparing for and conducting detention operations during LSCOs. It considers responsibilities for ensuring that detention operations comply with international law, notably the law of armed conflict (LOAC).

Preparation for Detention Operations

In international armed conflict, LOAC sets out detailed detention regimes related to both prisoners of war (POW) and interned civilians. The detaining power bears full responsibility for the treatment afforded to POWs and interned civilians, including ensuring their detention complies with LOAC. Prior to the commencement of any LSCO, therefore, States must ensure they have adequately prepared to detain both POWs and civilians, potentially on a very large scale.

The Importance of Training

The foremost responsibility prior to any LSCO is preparing for large detention operations to match the scope and scale of the conflict. All personnel, to include individuals both on and off the battlefield, must be properly trained and ready to engage in LOAC-compliant detention operations. This preparation includes, but is not limited to, understanding the treatment obligations for each class of detainee and anticipating the number and categories of individuals likely to be detained. The detainees could include enemy soldiers, civilians, and other actors whose status may not be evident, such as fighters belonging to an armed group or private military company. Further, the relevant roles and responsibilities must be delineated at each area of the battlefield, from the point of capture to the time of release. Detailed preparation will help ensure that detention operations are conducted in compliance with international law.

The United States is uniquely positioned to provide education on detention operations. It has conducted large-scale detention operations, albeit sometimes in a flawed manner, repeatedly in the last 50 years. Army Senior leaders must understand the basics of detention operations to ensure that they develop plans and policies that facilitate the design, development, and deployment of solutions to enable LOAC-compliant detentions. Further, as the United States’ strategic competitors build their strategic advantage and attempt to decrease U.S. legitimacy, the United States must provide basic detention operations familiarization training for senior leadership to provide a framework to counter these efforts.

It is not senior leaders, however, that are likely to directly engage in detention operations. Training must be provided to all military personnel to provide a deeper understanding of their responsibilities when conducting detention-related activities. Activities related to detention are highly specialized and perishable skills. Building this expertise can only be accomplished through training and time.

To ensure the United States respects LOAC in its detention operations, the U.S. military conducts muti-tiered training related to all aspects of detention operations. LOAC familiarization is incorporated into training for all Service members from basic combat training to the General Officer leadership courses. Soldiers are further trained how to apply the concepts of LOAC when initially conducting detention operations on the battlefield, primarily at the point of capture and when transporting detainees to another location for further case reviews and potentially longer periods of detention.

The U.S. Army is the Executive Agent for detention operations and the experts with responsibility for such operations are the U.S. Military Police. They receive in-depth training at Fort Leonard Wood based on their military occupational specialty and in courses such as the Corrections and Detention Course. In addition, they practice large scale detention operations during exercises such as DEFENDER-Europe. Consistent training on detention operations helps ensure soldiers understand and act consistently with LOAC, including regulations regarding the establishment of detention facilities in a combat zone and the treatment of detainees.

Training undertaken prior to any LSCO must relate not only to the detention of POWs but also to civilian internees. Civilian internment is temporary and only used for security reasons. Interned civilians must be released as soon as the reasons for internment no longer exist. Holding significant portions of the population in detention for prolonged periods of time based on security concerns is unsustainable and associated historically with defeat. During World War II, German detentions of vast numbers of civilians did not provide Germany a military advantage nor contribute to victory. Large-scale civilian incarceration is counterproductive because of the resources it requires and the absence of any clear strategic or military value.

Conversely, the detention of large numbers of POWs during LSCOs is almost inevitable. POW detentions are often lengthy, logistically demanding, and resource intensive. Although POWs must normally be released and repatriated without delay at the end of active hostilities, factors such as their health, parole policies, criminal prosecution, and special agreements between States may necessitate extended detention. Hence, the detention of POWs in LSCOs requires detailed planning, well in advance of the conflict’s commencement.

The Impact of Disinformation, Propaganda, and New Technologies

Preparation and training for detention operations must also take account of the operational environment, including the influence of technology. Disinformation and propaganda will become the operational norm, ranging from low-tech dissemination of false narratives via social or state-sponsored media to a full array of cyber-enabled capabilities that amplify misinformation to targeted populations. Military forces engaged in LSCOs must ensure that they are prepared for disinformation, misinformation, and propaganda, which will affect population flows and detention operations.

The conflict in Ukraine demonstrates the impact of disinformation and propaganda on detention operations. In March 2022, a video circulated allegedly showing Ukrainian troops shooting Russian prisoners. Ukraine denied these claims, alleging that the videos were fake. The real or perceived ill-treatment of prisoners by a detaining power can lead to violence and make it more difficult to gain the trust of local populations or convince troops to surrender. Russia uses propaganda and social media information warfare to exacerbate division and this same tactic can sow discord between allies. For example, Russia used the deaths of over 50 POWs on July 29, 2022 at the detention facility Olenivka, Donetsk Oblast, in multiple ways. One narrative included Ukraine misusing weapons provided by Western allies to perpetuate or cover-up war crimes.

In this way, disinformation and propaganda can be used to incite anger and violence against the detaining power, decrease its legitimacy, and make it difficult to promote negotiations for a peaceful resolution of the conflict. With the rise of deepfake technology, identifying and countering this propaganda will be critical. When preparing for detention operations in LSCOs, States must be ready to address the challenges posed by disinformation, potentially enhanced by new technologies. This will be essential to build legitimacy and trust with the public and to promote peacebuilding efforts.

Roles and Responsibilities During Detention Operations

A key obligation for all detaining authorities is to treat detainees humanely. The commander has a legal obligation to provide for the safe, secure, and humane detention or internment of all individuals captured on the battlefield. Importantly, the detaining power must ensure that all detainees, whatever their status, are provided with adequate food, water, shelter, and medical care. They must be treated without adverse distinction and promptly released when the circumstances justifying their detention no longer exist.

Although States have a legal obligation to detain and bring to trial suspected war criminals, military commanders are under no legal obligation to hold any other category of detainee. For operational reasons, a commander may therefore choose to release detainees or to curtail ongoing detention operations. Previous conflicts show that the United States has often underestimated likely detainee populations. This has negatively impacted the US military’s ability to provide the necessary support to detainees and has resulted in rapid releases with attendant security risks.

To avoid such risks, military commanders cannot choose between conducting LOAC-compliant detention operations and a successful military operation. Commanders cannot sacrifice the law for national advantage. States must accept full responsibility for detention operations when planning LSCOs and be ready to fulfill their obligations under LOAC from the point of capture to the time of release.

Yet, complexities on the modern battlefield present considerable challenges to the conduct of LOAC-compliant detention operations. As can be seen from the conflict in Ukraine, LSCOs might involve a wide variety of actors including members of non-State armed groups, foreign fighters, and private military contractors. These individuals may or may not belong to a party to the conflict, meaning that it may not be clear whether they are entitled to POW status. In accordance with LOAC, the United States treats all detainees whose status is in doubt as POWs until an Article V tribunal determines that they are not entitled to this status. However, there is a requirement to prepare for the screening and categorization of detainees and support their welfare in all circumstances, well before a LSCO commences.

The conduct of screening and the establishment of Article V tribunals to determine the status of detainees are matters for rear area commanders during LSCOs. These processes will inform a local commander’s decision whether to release or to continue to hold individuals under the military forces’ control. Commanders may also need to be prepared for the possible criminal prosecution of detainees for LOAC violations. In addition, they will need mechanisms to determine the security risk posed by civilian detainees. These screening measures are integral to staff planning to ensure that the military can secure and humanely hold and transfer detainees.


The future of combat will include both small and large-scale combat operations, with offensive and defensive actions being executed by a range of actors, including uniformed personnel, armed groups, private contractors, and civilians. Personnel whose status may not be evident are likely to be detained in multiple combat areas, on land or at sea. During LSCOs, the roles and responsibilities of the detaining force during detention operations are particularly complex and challenging, to include emerging threats arising from disinformation and propaganda. All actors involved in these operations are responsible for ensuring that they comply with international law. By fulfilling these obligations, military personnel and others that act on behalf of the detaining authority can help ensure that detention operations are conducted fairly, humanely, and lawfully.

The views, concepts, and statements expressed herein are the authors’ personal views and do not reflect the views of the Department of Defense or the Department of State.


COL William M. “Bill” Stephens is the Associate Dean for the Foreign Service Institute, School of Applied Information Technology and also a member of the U.S. Army Reserve.

Major Norberto O. Daluz is a Judge Advocate and serves as an Advisor with the National Security Law Division, Office of The Judge Advocate General.


Photo credit: Staff Sgt. Michael Pryor