abstract. Each day, the news brings stories of military attacks on schools, hospitals, apartment buildings, electrical facilities, and other critical civilian infrastructure. The militaries attacking these objects often seek to justify the attacks by claiming that the civilian objects are being used by militants. Objects that are believed to have both military and civilian use are often referred to as “dual-use” objects. Even though the term has become common, international law does not recognize a “dual-use” object as a legally meaningful category. Rather, the postwar Geneva Conventions that lie at the core of modern international humanitarian law establish a bright line between “military objectives” that are considered legitimate targets of military force, and civilians and “civilian objects,” which are to be strictly protected.

We show in this Article that the targeting of dual-use objects over the last several decades has blurred this line, placing civilians at great risk. The United States has played a critical role in the increasingly expansive targeting of dual-use objects. Indeed, most accounts of the origins of dual-use targeting start with the 1991 Gulf War, in which the U.S.-led coalition responded to Iraq’s occupation of Kuwait with airstrikes on Iraq’s electrical infrastructure and bridges. The Article reviews the history of dual-use targeting and presents an original dataset and primary-source evidence from the sites of U.S. airstrikes in Iraq and Syria from 2014 to 2018 to illustrate the wide range of dual-use objects that the U.S. military has struck. It draws on ground reporting and research to show the true costs of this dual-use targeting for civilians living in areas of conflict. The United States is far from alone in targeting dual-use objects, but we focus on it because it shapes the law of armed conflict by projecting force around the world, providing legal justifications for its use of force, and setting the standards by which other states are measured. Finally, this Article recommends that states engaging in military operations collect better information about dual-use objects so that they can make better-informed targeting decisions. We also offer several recommendations for clarifying international humanitarian law to prevent further erosion of the protections the law provides to civilians during war.

authors. Oona A. Hathaway is Gerard C. and Bernice Latrobe Smith Professor of International Law, Yale Law School. Azmat Khan is Patti Cadby Birch Assistant Professor, Columbia Journalism School; investigative reporter, New York Times and New York Times Magazine. Mara R. Revkin is Associate Professor of Law and Political Science, Duke Law School. To respect the boundaries of her role as a journalist, Azmat Khan did not contribute to Part III or any other mention of reform. Thanks to Jacob Levin, and especially Ben Menke, Ako Ndefo-Haven, and Vinay Sriram for excellent research assistance, and to Meghna Melkote and Katherine French for editorial assistance. Our thanks to Federica Du Pasquier, Laurence R. Helfer, Zachary Liscow, Samuel Moyn, Nicholas Mull, Ian Park, John Fabian Witt, and participants in the Yale Law School faculty workshop for their very helpful feedback. Our thanks to the team at Feeling Data & Hampshire Analytics for their outstanding data visualizations. This Article is informed by interviews, conducted by Oona A. Hathaway on background, with U.S. military officials. After consultation with Yale University’s Institutional Review Board (IRB), these interviews were determined not to be subject to IRB review under IRB Protocol ID 2000035963. This Article is also informed by field research, surveys, and interviews conducted by Mara R. Revkin and approved by Yale University under IRB Protocol IDs 2000022022 and 1506016040 and by Duke University under IDs 2023-0565 and 2023-0560. Revkin’s work on this Article was supported by the Economic and Social Research Council UK [Grant Reference: ES/X01097X/1; SBE-UKRI: Cumulative Civilian Harm in War] and National Science Foundation Award No. 2336310. This project was also supported by the Oscar M. Ruebhausen Fund at Yale Law School. A detailed Appendix, together with the data, R code, and instructions needed to replicate results reported in this Article, is available at https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/CGGQTY. In addition, dynamic versions of the data visualizations are available at https://dualuse.law.yale.edu.

Introduction

In April 2024, Israeli troops withdrew from al-Shifa Hospital, the largest medical complex in Gaza, leaving it in ruins.1 The Israel Defense Forces (IDF) claimed that Hamas had established a headquarters inside the hospital and that the operation had killed hundreds of militants, though independent reporting cast doubt on those
claims.2 The raids and bombings around the complex also killed large numbers of civilians, including patients and medical staff.3 Al-Shifa is far from alone, as the conflict “has seen hospitals targeted with an intensity and overtness rarely seen in modern warfare.”4 In December 2024, the Office of the United Nations High Commissioner for Human Rights reported that attacks by the IDF had resulted “in the killing of medical staff, patients and IDPs” located in and around the facilities, “pushing the healthcare system to the point of almost complete collapse.”5 In early May 2025, the World Health Organization assessed that there had been 686 attacks on health facilities, damaging at least thirty-three of Gaza’s thirty-six hospitals.6 Israel has defended the attacks as justified by Hamas’s use of medical facilities for military purposes, but the Associated Press found “Israel has presented little or even no evidence of a significant Hamas presence” in the cases it investigated.7

Throughout its war in Ukraine, Russia has attacked electrical facilities in the country. A study of the war identified 223 instances of Russian strikes on Ukraine’s power infrastructure over seven months.8 The impact on Ukraine’s civilians has been devastating, leaving millions without electricity, water, or heat in life-threatening winter temperatures.9 After a strike on a power station in Kyiv in April 2024, Putin explained that “in this way we will affect Ukraine’s military industrial complex and in a very direct way.”10

In Syria, on the evening of March 20, 2017, aircraft from the U.S.-led coalition attacked a three-story building in the Raqqa countryside it identified as an ISIS11 “intelligence headquarters and weapons storage facility” where “more than 30 ISIS militants typically stayed.”12 The coalition maintained that the target “was exclusively used by and under the control of ISIS” and that “no civilians had been harmed.”13 But a Human Rights Watch (HRW) investigation, based on multiple visits to the site and over a dozen interviews with survivors and eyewitnesses, told a different story: the building had served as a boarding school called the “Badia school” until 2011, when it began to host families displaced by the war.14 While local residents said ISIS had some presence, the building also housed a large number of civilians completely unaffiliated with ISIS.15 Survivors told harrowing accounts of waking up to explosions, finding relatives covered in shrapnel, and collecting the bodies of men, women, and
children.16 HRW documented at least forty civilians—including fifteen women and sixteen children—who were killed, but it believed the actual number was higher.17 Some estimates were in the hundreds.18 The coalition later admitted forty civilians had been killed, at which point they described the target as an ISIS “militant multifunctional center.”19Such strikes were also common during U.S. anti-ISIS operations in Iraq, where ISIS forces often operated from buildings in dense urban environments where civilians also lived and worked.

The targets of these attacks in Gaza, Ukraine, and Syria are what some have dubbed “dual-use” objects—meaning that, according to the militaries targeting them, the objects have both military and civilian uses.20 International law does not recognize a formal category of “dual-use” objects.21 Indeed, a critical innovation of the postwar Geneva Conventions, which lie at the core of modern international humanitarian law, was to establish a bright line separating “military objectives,” which were deemed legitimate targets of military force, from civilians and “civilian objects,” which were to be strictly protected.22 That bright-line distinction meant new and important protections for civilians in war. The gradual rise of the idea of dual-use objects over the last several decades, however, has blurred this line.

A variety of objects might be considered dual-use. A first set of dual-use objects are objects that, by their nature, serve or have the potential to serve civilian and military purposes alike—for example, transportation infrastructure like bridges, roads, trains, and airports.23 A second set of dual-use objects are civilian objects that become dual-use because they are used by armed groups—for example, an apartment building that houses civilian families might become a dual-use object if part of it is used as a storage facility for weapons or a meeting place for an armed group. A third set of dual-use objects are civilian in nature, but at least in part support or sustain armed forces or their members—for example, banks, bakeries and other food-production facilities, or oil wells and refineries (where some of the proceeds of oil sales go to the armed forces). These objects are sometimes referred to as “war-sustaining” because they support or sustain the enemy’s war effort, even though they are equally essential to civilians.24

The rise of the concept of dual-use objects has not served to protect civilians. To be sure, many of the objects that are today labeled “dual-use” have long been considered lawful “military objectives” under international humanitarian law. And calling these objects “dual-use” recognizes their civilian use. Yet it appears that, rather than prompting caution in targeting, dubbing objects “dual-use” has had the effect of creating a porous category of targetable objects that are obviously critical to civilian life and yet are lawfully targetable—including traditionally protected objects such as private homes, schools, and hospitals. Thus, while this Article is fundamentally concerned with what states do—that is, the targeting of dual-use objects—we also note that the creation of this category appears to have had the effect of casting suspicion on objects critical to civilian life, thus reducing inhibitions in targeting them. Global audiences have become accustomed to witnessing the destruction of these objects when the targeting military asserts that they serve some military purpose, however modest and however poorly documented. At the same time, the range of dual-use objects targeted in recent decades has grown in both type and scale. The addition of “war-sustaining” objects to the list of targetable objects—a development that is still contested—has significantly expanded the type of dual-use objects that are considered targetable. That greater willingness to target such objects presents a dangerous challenge to modern international humanitarian law and its aim to protect civilians from the worst horrors of war.

As we will show, the United States has played a critical role in both popularizing the idea of dual-use objects and spreading the practice of targeting such objects. The United States deployed the concept in the context of air warfare during the 1991 Gulf War, in which the U.S.-led coalition’s response to Iraq’s occupation of Kuwait included airstrikes on Iraq’s electrical infrastructure and bridges.25 The practice became widespread in the decades following the 9/11 attacks, as the United States waged war against nonstate armed groups, the members of which are often embedded in and difficult to distinguish from the civilian population.26 The difficulty of distinguishing between combatants and civilians and between military objectives and civilian objects is especially pronounced in conflicts involving nonstate armed groups that capture territory and attempt to govern civilian populations, including conflicts involving al-Qaeda and ISIS.27 Battles against such groups are often fought in or near urban civilian population centers—what military practitioners describe as “complex battlespaces.”28 In these conflicts, civilians and combatants rely on the same critical infrastructure, shelter, and sources of financial support. As the range of objects considered dual-use has expanded and as wars are increasingly waged in complex battlespaces, we now see conflicts in which dual-use objects are everywhere—and civilians suffer as a result.

The situation is made worse by armed groups that use the difficulty of distinguishing between their members and civilians to their advantage, embedding their activities in areas with large numbers of civilians whom they exploit as human shields, in an act some have referred to as “lawfare”—the use of legal rules by nonstate actors and other groups to undermine the advantage of their more powerful law-abiding adversaries.29 Although these armed groups are to blame for entrapping civilians and, in some cases, “baiting” counterinsurgents into attacking them,30 the concept of dual-use objects plays into their hands by dramatically expanding the scope of legitimate targets to include almost anything. Indeed, when conflict takes place against nonstate actors in densely populated areas, much of the infrastructure and underpinnings of the economy critical to civilian thriving might be labeled dual-use objects.

The rise of dual-use objects and the accompanying erosion of the bright line between civilian objects and military objectives have produced contradictions in states’ positions on targeting objects that may be considered dual-use. For example, the United States has in the past attacked electrical power systems. One paper by a U.S. Air Force major in 1994 claimed that “[e]lectric power has been considered a critical target in every war since World War II.”31 And, indeed, the U.S. Department of Defense’s (DOD’s) Law of War Manual states that electrical power stations are “generally recognized to be of sufficient importance” to a state’s military functions “to qualify as military objectives during armed conflicts.”32 Yet, when Russia fired missiles at Ukraine’s energy grid, Chairman of the Joint Chiefs of Staff Mark Milley told reporters that “the deliberate targeting of the civilian power grid, causing excessive collateral damage and unnecessary suffering on the civilian population is a war crime.”33

Some of the worst suffering by civilians in wars taking place today has happened as a result of targeting dual-use objects. In Gaza, Israeli attacks have targeted not only hospitals but also schools,34 the electrical grid,35 agricultural production,36 camps for displaced persons,37 and apartment buildings.38 The IDF has justified these strikes as aimed at members of Hamas, its command-and-control centers, and its weapon-storage facilities.39 Whether those claims are accurate or not, the result has been the utter devastation of Gaza’s critical infrastructure, which will take billions of dollars and a generation to rebuild.40 In Ukraine, too, critical infrastructure has been subject to devastating attacks. While it is less clear that Russia, which rarely explains the legal justifications for its targeting decisions, has targeted these objects as dual-use objects rather than simply ignoring international humanitarian law’s protections for civilian objects, the end result is much the same: civilians have lost access to schools, public transportation, reliable electricity, and more.41

Importantly, the rise of the concept of dual-use objects has not only affected targeting. In the provision of humanitarian aid, it has also led to restrictions on essential items such as pipes, water filters and pumps, spare parts for electrical generators, and even medical scissors.42 Such restrictions may hinder armed groups, but they can also cripple efforts to meet the basic humanitarian needs of civilians. Beyond areas of conflict, there are extensive export controls on dual-use goods and technology43—and an ever-growing list of items subject to such controls.44

Part I of this Article reviews the historical development of the concept, law, and practice of dual-use targeting. We show that dual-use targeting has been shaped heavily by the United States and its close ally Israel but is increasingly used by a growing number of other states, including U.S. rivals and nondemocracies like Russia, Iran, and Saudi Arabia.45

Part II presents primary-source evidence from the sites of U.S. airstrikes in Iraq and Syria from 2014 to 2018 to illustrate the wide range of objects that the U.S. military has either explicitly or implicitly identified as dual-use. We focus on the United States because it plays an outsize role in shaping the law of armed conflict as a result of its capacity to project force around the world, its efforts to provide legal justifications for its use of force, and its role in setting the standards by which other states are
measured.46 We also have more detailed information about U.S. use of military force in Syria and Iraq than in any other contemporary military conflict. Using an original dataset constructed from DOD’s strike releases, we show that dual-use objects have been targeted in U.S. military operations.47 We then use documents obtained from DOD under the Freedom of Information Act (FOIA), as well as ground reporting and field research by two of the authors, to show that the targeting of dual-use objects is far more common than these public disclosures suggest—and the human cost to civilians even more grave. This evidence helps demonstrate that the rise of dual-use targeting has come to threaten core principles of international humanitarian law, particularly the principles of distinction and proportionality.

Part III offers recommendations for reforms to better protect civilians and prevent further erosion of foundational legal commitments of the postwar legal order.48 As Part II makes clear, states often know very little about how the destruction of dual-use objects will affect the civilian population. We thus recommend that states engaging in military operations collect better information about dual-use objects that are critical to civilian well-being in areas of conflict so that they can anticipate, and take steps to mitigate, the impact of their targeting decisions on civilians. We also offer several recommendations for clarifying international humanitarian law to account more effectively for—and thus more effectively prevent—the grave harm that targeting dual-use objects inflicts on civilians during war, with effects that can be felt for generations.