Dual-Purpose Objects
Editors’ note: This post is based on the authors’ recently published article “On the Purpose Limb of the Military Objective Test under the Law of Targeting” published in volume 64 of Military Law and Law of War Review.
The concept of dual-use objects is misleading. It is not a formally recognized legal concept under the modern law of armed conflict. Rather, the law maintains a binary distinction between military objectives and civilian objects; there is no intermediate legal category (Department of Defense, Law of War Manual, § 5.6.1.2). Once an object meets the criteria for a military objective—namely, that by its nature, location, purpose, or use it makes an effective contribution to military action and its destruction, capture, or neutralization offers a definite military advantage—it may lawfully be made the object of attack. Its continued civilian uses do not preserve its status as a civilian object.
Moreover, military objectives are not limited to objects currently in military use. Under Article 52(2) of Additional Protocol I, an object may qualify as a military objective when there is sufficient basis to believe that it contributes to military action by its purpose. This forward-looking dimension of the test extends the scope of lawful targets beyond objects presently employed for military ends to those with a prospective or intended military use.
In a recent article, we examine this “purpose” limb of the military objective test in greater depth, focusing on its historical development and its treatment in State practice. That analysis demonstrates that certain categories of ostensibly civilian infrastructure have long been regarded as legitimate military objectives due to their design intent or latent military potential. Contrary to popular beliefs, oil refineries and other enemy infrastructure have long been recognized as military targets. Rather than rehearsing standard legal analysis, this post considers the implications of this finding for the legal characterization of civilian infrastructure that is likely to assume heightened military significance in future conflict.
Satellites
It is widely known that commercial satellite systems have provided critical support to military forces across a range of mission areas, including intelligence, surveillance, and reconnaissance (ISR); positioning, navigation, and timing (PNT); and communications. High-resolution imagery from companies such as Vantor (formerly Maxar Technologies), Planet Labs, EagleView, and BlackSky has been routinely used to supplement governmental ISR capabilities, offering timely and flexible access to global observations.
In the PNT domain, while the U.S. Global Positioning System (GPS) remains a military cornerstone, commercially augmented services such as those enabled by companies like Trimble and Hexagon enhance accuracy and resilience against electronic warfare, ensuring accurate navigation in contested environments. Similarly, commercial communications satellites operated by firms such as SpaceX and Viasat have provided real-time connectivity for deployed forces, especially in contested or remote environments where access to dedicated military satellites may be limited or non-existent.
Beyond these established military uses, the potential of commercial satellite systems extends to a broader spectrum of capabilities that are either designed with defense applications in mind or are inherently adaptable for military purposes despite being developed for civilian or commercial markets. This dual-purpose character has become increasingly salient in recent years. Contract issues surrounding Space X’s Starlink services recently illustrated how a single commercial satellite network can support different types of users through tiered service offerings and differentiated access arrangements. The reported contractual problem highlighted that even when a satellite system is not formally dedicated to military use, its commercial functionality can be used to meet operational military requirements.
In addition, certain satellites may be characterized as dual-purpose space systems, even when they serve exclusively civilian functions in peacetime. For example, satellites designed for benign purposes, such as debris removal or on-orbit servicing, have potential to be repurposed to harm other space objects due to their characteristics or capabilities. Indeed, the concept of dual-purpose has already entered space policy discourse to capture this latent capability, distinguishing satellites with potential military applications from dual-use systems that are employed to perform both civilian and military functions. Such space objects, even when not engaged in military activity at the time of an attack, may nonetheless constitute military objectives when their design intent or inherent characteristics, under the circumstances prevailing at the time, enable them to make an effective contribution to an adversary’s military action.
Caution is nevertheless warranted before assuming the applicability of the law of targeting to military operations in the space domain, given the geographically confined scope of this body of law. As discussed elsewhere, the rules governing targeting have been developed to regulate battlefield conduct in the terrestrial environments and, as such, their direct transposition to outer space must not be presumed. However, to the extent that an attack on a space object is reasonably expected to produce the requisite harmful effects—namely, death, injury, damage, or destruction—within the terrestrial context, there are compelling grounds to extend the application of targeting law to dual-purpose satellites. This is particularly pertinent where their destruction or disruption may foreseeably result in cascading consequences on Earth, such as transportation collision or the failure of critical services upon which human life may depend.
Data Centers
In basic terms, data centers are physical facilities that house multiple computer servers, data storage devices, and network equipment used to store, process, manage, and transmit large amounts of data and applications. A data center, therefore, is not a singular object, and determining whether a center itself constitutes a military objective requires an analysis of its component parts. Data centers are broadly comprised of three elements: physical facilities and support infrastructure; servers and network equipment; and data and applications. Each of these different components must be evaluated when considering whether a data center qualifies as a military objective.
Physical structures and support systems, such as environmental control equipment and uninterruptible power supply units, are unlikely to be military objectives by nature unless they constitute an integral part of military infrastructure. Similarly, a data center’s buildings and service systems are unlikely to be military objectives by location except when they are situated at a place that is already of military significance, such as a military base. Nevertheless, these facilities may qualify as military objectives when, for example, data centers store and process military intelligence, host cloud services, or provide computing power necessary for AI-assisted logistics, target identification, and predictive battlefield analysis. The targetability of a data center, therefore, frequently will depend on the use or expected use of the center’s equipment, data, and applications.
Due to the prominence of data centers for AI applications, data centers may qualify as military objectives even when military forces are not making use of them for military action. Ownership of a data center’s information technology infrastructure or a contract providing for the equipment’s military use can be a sufficient indicator of an adversary’s intended future use. Servers and networking equipment, whether owned privately or by military forces, that have the specific capabilities to serve a military interest could also qualify as military objectives. For instance, privately owned servers may be capable of establishing secure network connections that are expected to sustain operational data analyses. Specialized computers equipped with exceptionally high processing power, processing speed, or high-density storage capacity may be assessed to offer alternative sources of computing power necessary to conduct real-time battlefield simulations. Indeed, the nuclear simulations conducted as part of the United States’ Stockpile Stewardship program would be an example. The Advanced Simulation and Computing program that supports the Stockpile Stewardship effort relies on the extraordinary computational power of El Capitan, one of the world’s fastest supercomputers, located at the Lawrence Livermore National Laboratory in California.
Importantly, to qualify as a military objective, an object’s destruction, capture, or neutralization must also offer a definite military advantage in the circumstances ruling at the time. Assessing military advantage, therefore, is critical to determining the targetability of a data center. A server used to store sensitive military satellite imagery might make an effective contribution to military action, but if the same information is stored in multiple locations, the destruction of the single server might not provide the requisite military advantage (p. 217–18). By the same token, high value servers and specialized computers may not qualify as military objectives, no matter how valuable they may be for the adversary’s military action, when multiple alternative solutions exist. In general, however, the internet’s ability to reroute data and tasks across a vast network of servers and storage devices suggests that determining the military advantage of more common cyber capabilities is not straightforward.
3D Printers
In recent years, 3D printing technology, also known as additive manufacturing, has become a staple of military production. With the growing prominence of drone warfare, Ukraine has transitioned toward a highly decentralized, small-scale, and dispersed manufacturing model to protect its defense industrial base from Russian strikes. This shift reflects a broader reality of modern warfare, where large, fixed production facilities are highly vulnerable to precision-guided missiles and loitering munitions. In response, the distribution of production across concealed, underground, or mobile sites by utilizing 3D printing and commercial off-the-shelf technologies has become essential to ensure that no single strike can significantly degrade national manufacturing capacity.
Due to its ability to produce highly detailed and complex objects at the scale and speed of relevance, additive manufacturing promises significant advantages in terms of production speed, flexibility, and efficiency on the battlefield. However, additive manufacturing hardware such as 3D printers is inherently application-agnostic, allowing it to shift from producing advanced prosthetics for civilian medical care to critical fighter jet components simply by loading a different software file. For example, using standard plastic materials, a single 3D printer can produce both benign consumer items, such as smartphone cases, and military equipment, including plastic guns or structural components for first-person-view (FPV) drones such as frames and battery mounts.
Although generally classified as dual-use technology for arms export purposes, the legal characterization of such devices as military objectives does not necessarily depend on demonstrated military use. One of their defining features is on-demand flexibility. A small civilian engineering shop or even a workshop garage can instantly pivot existing 3D printers into defense manufacturing hubs without the need for specialized machinery. This latent military potential, combined with the growing reliance on additive manufacturing for dispersed and adaptable battlefield production, provides compelling grounds for characterizing such devices as dual-purpose objects. Accordingly, they may qualify as military objectives where, in the circumstances prevailing at the time, they are assessed as making an effective contribution to an adversary’s military action and where their destruction, capture, or neutralization offers a definite military advantage.
Concluding Observations
This brief discussion offers only a preliminary assessment of how cutting-edge civilian infrastructure in an increasingly interconnected world may, under certain conditions, qualify as military objectives by virtue of their dual-purpose character. The mere identification of such infrastructure, whether satellites, data centers, or advanced manufacturing systems like 3D printers, should not lead to any presumption of targetability. The applicability of targeting law remains contingent on context, including the object’s location, and where this legal framework applies, the determination of targetability hinges equally on the commander’s good faith assessment that the object makes an effective contribution to the adversary’s military action and that its destruction, capture, or neutralization offers a definite military advantage.
Nevertheless, as digital interdependence deepens and the battlespace expands beyond traditional domains, the “purpose” limb of the military objective test is likely to assume increasing prominence. This evolution may render emerging forms of critical infrastructure, such as those discussed above, susceptible to lawful targeting even before their demonstrated use by an adversary.
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Ronald Alcala is a Colonel in the United States Army. He is an Academy Professor of Law and Associate Dean for Strategy & Initiatives at the United States Military Academy, West Point, N.Y. He also serves as Executive Editor of Articles of War and Executive Editor of the West Point Press.
Hitoshi Nasu is a Professor of Law in the Department of Law and Philosophy at the United States Military Academy.
The views expressed are those of the authors, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.
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