Análisis técnico-jurídico de las posibilidades de la Artillería Antiaérea ante la Amenaza de los sUAS
LEGAL REVIEW Castro Milla, José Manuel. “Análisis técnico-jurídico de las posibilidades de la Artillería Antiaérea ante la Amenaza de los sUAS.” Boletín CODESEL, vol. 2, no. 10, August 2026, ISSN-e: 3045-7750. Review Few technological developments have transformed contemporary military operations as rapidly as the proliferation of small unmanned aerial systems (sUAS). Once largely confined to technologically advanced armed forces, unmanned aerial capabilities have become increasingly accessible to state and non-state actors alike, profoundly altering the relationship between offensive capability, defensive preparedness and technological superiority. In this timely and highly relevant article, José Manuel Castro Milla examines the technical and legal challenges posed by sUAS to modern Air Defence Artillery, arguing that traditional air-defence architectures must evolve towards integrated, multidomain and increasingly automated counter-UAS systems capable of responding to threats characterised by low cost, reduced signatures and extremely short decision cycles. The article begins by placing the problem within the broader transformation of Force Protection. Rather than approaching the defence of military installations as a static or essentially logistical function, Castro Milla presents it as an increasingly strategic requirement directly connected with operational freedom of action. Particularly effective is the use of Alan Vick’s Snakes in the Eagle’s Nest as an analytical framework: the protected military base becomes the “nest”, while the emerging asymmetric threat constitutes the “snake” capable of circumventing conventional defensive advantages. The metaphor successfully illustrates how inexpensive and commercially available technologies can challenge sophisticated military systems and force established air-defence structures to reconsider their assumptions. One of the article’s principal strengths lies in its examination of the so-called “Second Drone Age”. Castro Milla identifies the proliferation of Low, Slow and Small systems as a fundamental disruption of traditional air-defence models. Reduced radar cross-section, limited infrared and acoustic signatures and unconventional flight profiles allow many small drones to operate precisely within the technological gaps of systems originally designed to detect and intercept larger, faster and more predictable aerial targets. The author further emphasises how artificial intelligence, autonomous swarm coordination, fifth-generation communications and beyond-line-of-sight connectivity are expanding the operational potential of these systems. The discussion of technological asymmetry is particularly convincing. The article correctly highlights that the significance of sUAS does not derive solely from their technical sophistication, but from the disproportion between their acquisition cost and the value of the military assets they can threaten. The 2018 attacks against the Russian bases of Khmeimim and Tartus provide a useful illustration of this phenomenon: relatively rudimentary unmanned platforms were capable of creating a significant defensive challenge for forces equipped with advanced air-defence systems. The case demonstrates one of the defining characteristics of contemporary warfare: technological effectiveness increasingly depends not simply upon possessing the most expensive system, but upon exploiting vulnerabilities within the adversary’s defensive architecture. Castro Milla’s analysis of the necessary response is equally valuable. Rather than proposing a single technological solution, the article advocates a genuine “system of systems” integrating detection, tracking, command and control, data fusion and multiple categories of effectors. Active radar sensors must operate alongside passive radio-frequency, acoustic and electro-optical/infrared systems, while the resulting information must be fused into a coherent low-altitude operational picture. This layered approach reflects the essential difficulty of the counter-UAS mission: no individual sensor or weapon can adequately address the full spectrum of small unmanned threats. Particularly significant is the article’s treatment of automation and human control. Saturation attacks involving numerous simultaneous targets compress the decision-making process to such an extent that conventional human-in-the-loop models may become operationally insufficient. Castro Milla therefore examines the transition towards human-on-the-loop architectures, in which automated systems identify, classify and prioritise threats while retaining human supervision over the ultimate use of force. This is one of the article’s most important contributions because it directly connects technological development with the legal and ethical problem of human control over increasingly autonomous military systems. The challenge is no longer simply how rapidly a defensive system can react, but how legal responsibility and operational supervision can be preserved when machine-speed decision-making becomes indispensable. The examination of directed-energy weapons further reinforces the forward-looking character of the study. High-Energy Lasers and High-Power Microwave systems are presented as particularly promising countermeasures against sUAS, especially where conventional interception would impose an unsustainable economic or logistical burden. Their virtually negligible cost per engagement, rapid response and potential for repeated use make them attractive against massed drone attacks and loitering munitions. High-power microwave systems are especially relevant in this context because their effects may extend across multiple electronic targets simultaneously, offering an important response to the problem of autonomous swarms. Nevertheless, the article does not fall into technological determinism. Castro Milla appropriately recognises the limitations affecting directed-energy systems, including atmospheric interference, substantial energy requirements and the broader operational conditions governing their effectiveness. The discussion of loitering munitions is especially useful because these systems create what may be described as a persistent threat window: unlike conventional missiles, they can remain within an operational area while awaiting an appropriate target. Defensive systems must therefore combine rapid reaction with persistence and economic sustainability, precisely the characteristics that directed-energy weapons may increasingly provide. The legal dimension constitutes another major strength of the study. Castro Milla correctly distinguishes between counter-UAS operations conducted within national territory during peacetime and those undertaken in the context of armed conflict. The applicable rules concerning the use of force, hostile intent, competence and rules of engagement differ substantially between these environments. Within the Spanish framework, the author additionally stresses the importance of coordination between the Armed Forces and the State Security Forces and Corps, together with the integration of military and civilian airspace-management capabilities. This institutional perspective substantially enriches what might otherwise have remained an exclusively technical analysis. Particularly noteworthy is the connection established between counter-UAS technologies and the principles governing the conduct of hostilities. The author argues that non-kinetic effectors and directed-energy systems may contribute to compliance with the principles of distinction and proportionality by reducing the collateral risks associated with conventional kinetic interception, particularly in urban environments or around critical infrastructure. This observation is highly relevant for contemporary military operations, where the effectiveness of an air-defence response must increasingly be assessed not merely in terms of whether a hostile platform can be neutralised, but also according to the consequences generated by the chosen method of interception. The conclusions successfully translate the preceding analysis into practical doctrinal recommendations. Castro Milla advocates the consolidation of integrated surveillance, control and coordination capabilities for the lowest layers of the airspace, the development of AI-assisted command-and-control systems operating under supervised autonomy and a renewed emphasis upon passive defence, multispectral concealment, deception and resilience. Particularly valuable is this final insistence upon passive protection. Counter-UAS defence cannot depend exclusively upon detecting and destroying hostile platforms; it must also reduce the enemy’s capacity to identify, classify and successfully engage valuable targets. Methodologically, the article succeeds in combining operational analysis, emerging military technology, air-defence doctrine and legal reasoning within a compact and coherent framework. Its interdisciplinary character is especially appropriate to the counter-UAS problem, which cannot adequately be understood through a purely technological or purely legal perspective. Sensors, effectors, artificial intelligence, command structures, rules of engagement and legal constraints increasingly form parts of the same operational architecture. The visual dimension of the article also reinforces its argument. The photographs of systems such as M-LIDS and the Stryker DE M-SHORAD illustrate the transition from theoretical counter-UAS concepts towards deployable integrated solutions. Particularly significant is the latter system, which demonstrates the growing effort to incorporate high-energy directed-energy weapons into mobile short-range air-defence platforms, visually encapsulating the technological transformation discussed throughout the article. From a broader strategic perspective, the study highlights a fundamental transformation in the economics of air defence. Armed forces can no longer assume that technological superiority will automatically translate into defensive superiority when adversaries are capable of employing numerous inexpensive systems to saturate costly defensive architectures. The resulting challenge requires a combination of technological adaptation, organisational integration, doctrinal innovation and legal preparedness. Overall, this article constitutes a valuable and timely contribution to the study of contemporary Air Defence Artillery and counter-UAS operations. José Manuel Castro Milla successfully demonstrates that the challenge posed by small unmanned aerial systems extends far beyond the acquisition of new weapons. It requires a comprehensive transformation of detection systems, command-and-control architectures, defensive effectors, human-machine interaction and the legal frameworks governing the use of force. The study will be of particular interest to specialists in air defence, counter-UAS operations, emerging military technologies, defence policy, operational law and International Humanitarian Law seeking to understand how rapidly evolving unmanned threats are reshaping the defence of forces and critical infrastructure. Abstract This review examines José Manuel Castro Milla’s technical and legal analysis of the challenges posed by small unmanned aerial systems (sUAS) to contemporary Air Defence Artillery. The article situates the proliferation of Low, Slow and Small platforms within the “Second Drone Age” and argues that conventional air-defence architectures must evolve towards integrated counter-UAS systems combining active and passive sensors, artificial intelligence, command-and-control networks and both kinetic and non-kinetic effectors. Particular attention is devoted to supervised autonomy, directed-energy weapons, electronic warfare and the growing challenge of drone swarms and loitering munitions. The study also addresses the legal framework governing counter-UAS operations, including rules of engagement, hostile intent, civil-military coordination and the principles of distinction and proportionality. It concludes that effective defence against emerging unmanned threats requires not only technological innovation but also doctrinal adaptation, institutional integration, passive resilience and a robust legal framework capable of reconciling operational speed with human supervision and the lawful use of force.