The Battle for Legitimacy in Urban Warfare

In urban warfare, where combat unfolds amid a multitude of civilians and dense infrastructures, maintaining legitimacy is not merely a legal formality—it is a strategic imperative. According to U.S. military joint doctrine, legitimacy is one of the twelve principles of joint operations. Its purpose is to “maintain legal and moral authority in the conduct of operations,” and it is grounded in the “actual and perceived legality, morality, and rightness of actions from the various perspectives of interested audiences” to include national leadership, domestic populations, governments, local communities in the operational area, and international audiences.

A central challenge in urban warfare is navigating the complex regulatory environment that governs military operations. These regulations can be broadly categorized into three interrelated layers:

Law of Armed Conflict (LOAC) often also called ‘Law of War:’ This is the foundational framework established by treaties and customary international law rooted deeply in the history and logic of the military profession. It regulates the conduct of hostilities and protects victims of war, limiting deliberate violence to legitimate military targets, demanding the implementation of all feasible measures to reduce risk to civilians, and imposing rules (such as the proportionality rule) that remind warriors that even in war the ends cannot always justify the means. 

Rules of Engagement (ROE): ROE are policy limitations on otherwise lawful authority. In U.S. practice, they are operational directives issued by national command authorities or subordinate officers authorized to impose such limitations. They integrate legal mandates with strategic, operational, and political considerations. ROE are orders that must be complied with even when they are more restrictive than the underlying LOAC. They provide parameters within which military commanders must operate to accomplish their assigned mission. Importantly, ROE are adaptable and can (and often do) change rapidly in response to mission imperatives and reflect the evolving realities on the battlefield. It is important to note, however, that they may never authorize conduct that is prohibited by the LOAC.

Civilian Harm Mitigation Measures: As noted above, the LOAC requires implementation of all feasible measures to mitigate civilian risk during the conduct of hostilities. In order to enhance the protective effect of this obligation, supplemental policy initiatives have been designed and adopted to advance this humanitarian goal. For example, a command may restrict the authority of subordinate commanders to make proportionality judgments when the anticipated civilian risk exceeds a certain threshold. This does not mean that civilian harm below that threshold is always permissible. Instead, it is a precautionary measure intended to escalate decisions to higher levels of command whenever the risk exceeds the threshold. In so doing it allows for a more experienced judgment from a commander with broader perspective and tactical options.

Understanding the distinctions among these layers is crucial. While the LOAC establishes the legal framework for operational decision-making, ROE and civilian harm mitigation policies are dynamic tools that adjust to specific operational contexts.

Implementing this body of law and policy is always challenging, especially making the judgment of what civilian risk mitigation measures are feasible and when unavoidable civilian harm is excessive in comparison to the intended military advantage. But this challenge is especially daunting in the context of urban warfare, and even more so when fighting a nefarious enemy who pervasively violates international law. In this context, like any, these determinations are highly context dependent. For instance, during American counterterrorism operations, policies—exemplified by the Obama administration’s strike policy for the use of force outside areas of active hostilities, which was publicly acknowledged in December 2016—required a determination of near certainty of zero civilian casualties before a strike could be authorized. But this was never the policy in Afghanistan. More importantly, during what is called Large Scale Combat Operations (LSCO) -a high-intensity, peer-on-peer conflict - operational realities and military requirements will almost certainly necessitate a different civilian risk mitigation calculus where some degree of collateral harm may be unavoidable despite rigorous efforts to avoid it.

A telling example of the misunderstanding of the impact of operational context on legal and policy implementation comes from media coverage of Israel’s military operations in Gaza. Prior to October 7th, Israel’s engagements were evaluated under a counterterrorism framework that imposed stringent limitations on proportionality assessment authority. However, as hostilities escalated after the Hamas attack and invasion of Israel on October 7th, the operational context shifted dramatically. Instead of a counterinsurgency campaign relying almost exclusively on airpower, the IDF was compelled to launch a large-scale combined arms maneuver campaign involving approximately 100,000 ground combat forces to engage an enemy estimated to number between 30-40,000. This logically necessitated a recalibration of the rules of engagement and authority to make life proportionality assessments.

Despite this significant change in strategic imperatives, an interactive report by The New York Times report, “Israel Loosened Its Rules to Bomb Hamas Fighters, Killing Many More Civilians,” failed on two levels. First, the article did not clearly explain the difference between altering the civilian casualty threshold and the ultimate proportionality decision required within that threshold. Second, the article failed to acknowledge how a radical shift in operational context justified this change.

The shift from a counterterrorism paradigm to a large-scale ground campaign fundamentally alters the way the Law of Armed Conflict (LOAC) targeting framework is implemented, especially at the tactical level. This is not because the law itself changes, but because the conditions for its implementation do. In counterterrorism and counterinsurgency operations, especially those heavily reliant on air power, engagements are often deliberate, with targets identified through prolonged intelligence collection, surveillance, and precision strikes conducted with the luxury of time. This includes the opportunity to carefully model anticipated civilian harm. This allows for ‘tactical patience’, enhancing civilian harm mitigation.

However, combined arms maneuver warfare—such as the ground campaign Israel launched in Gaza—demands a fundamentally different approach to LOAC implementation. Close combat against a well-armed, entrenched enemy, particularly one that embeds itself within civilian infrastructure, often compels maneuver commanders and subordinate leaders to make split-second use-of-force decisions in the midst of battle. Unlike an air-centric counterterrorism approach where commanders often have the luxury of time and extensive attack resources to achieve their desired attack effects, ground forces in LSCO operate under a mission imperative to “close with and destroy the enemy by fire and maneuver.” This means synchronizing a range of combat power in real time, often while under fire, in an environment where the ability to conduct detailed proportionality assessments is drastically limited.

Crucially, the LOAC principles of distinction, precautions, and proportionality remain unchanged, but how those principles are implemented must adapt to the realities of high-intensity warfare. In LSCO, a commander may not have the luxury of waiting for a higher echelon to conduct an extensive collateral damage estimate before engaging the enemy. The very nature of combat in dense urban terrain—where enemy forces use tunnels, fortified positions, and civilian structures for military purposes—means that expectations for how LOAC should be applied in a counterterrorism context cannot simply be transposed to combined arms maneuver operations. To do so is to ignore the operational realities that fundamentally shape battlefield decision-making.

Expecting the same level of civilian harm mitigation in a major ground campaign as in an air-dominant counterterrorism operation is therefore not just unrealistic—it is operationally illogical. This does not mean the law is ignored or circumvented. Rather, it means that commanders must make attack-legality determinations based on the circumstances of LSCO, where the need for rapid decision-making and immediate force synchronization demands a different application of the same legal principles. Misunderstanding this distinction leads to unrealistic expectations that can delegitimize even lawful military actions and distort public perception of what compliance with the LOAC truly requires in the context of large-scale urban warfare.

Exacerbating the misleading nature of the NYT article was the way it addressed modifications of other IDF precautionary measures, such as protocols for observing potential enemy targets and warning tactics such as roof knocks: dropping low-yield explosive on top of buildings as warning shots that give civilians time to flee an imminent attack. But again, it failed to explain why extensive strike precautions taken by Israel in pre-October 7^th counterterrorism campaign logically be ill-suited to a high-intensity war against Hamas where military requirements might preclude such measures. By not distinguishing between the operational adjustments to civilian risk mitigation procedures, the New York Times report contributed to a distorted understanding of how context impacts LOAC implementation. This oversight underscores the vital importance of nuanced reporting that distinguishes between temporary policy adaptations and enduring legal principles.

In today’s information age, public perception plays a pivotal role in the legitimacy of military operations. When media outlets and advocacy groups conflate changes in tactical and operational procedures with indifference towards international legal standards, they risk undermining the credibility of even well-founded military decisions. Clear communication is essential—not only to explain the inherent differences between the legal obligations and the policies adopted to implement these obligations, but also to contextualize why these distinctions matter in varying operational scenarios.

The long-term negative consequence of such reporting and the overbroad condemnations it contributes to are profound. At a time when U.S. armed forces must once again contemplate LSCO, and some advocate a retreat from the legal and moral high ground, we cannot afford reinforcing unrealistic expectations of what the LOAC demands. Doing so will only provide greater momentum for those who unfortunately fail to recognize the moral and strategic value of the continuing commitment by U.S. armed forces to the rules of international law especially in war, and even when the enemy does not reciprocate such commitment. By recognizing the vital role operational context plays in assessing both actual and perceived legitimacy will ensure that the pursuit of strategic objectives does not come at the cost of eroding the very legitimacy upon which the moral and legal authority of military operations depends.

John Spencer is chair of urban warfare studies at the Modern War Institute, codirector of MWI’s Urban Warfare Project, and host of the Urban Warfare Project Podcast. He served twenty-five years as an infantry soldier, which included two combat tours in Iraq. He is the coauthor of Understanding Urban Warfare.

Geoffrey Corn is the George R. Killam, Jr. Chair of Criminal Law and Director of the Center for Military Law and Policy, Texas Tech University School of Law and a Distinguished Fellow with the Gemunder Center for Defense Strategy (part of the Jewish Institute for National Security in America). A retired U.S. Army Judge Advocate Officer, he served as the Army's senior law of war advisor.