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Lessons for South Korea’s Security from the Russia–Ukraine War: The Three Core Imperatives of Technology, Manpower, and Alliances |
| July 15, 2025 |
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Kwang Sup JooVisiting Research Fellow, Sejong Institute | myjohj1@naver.com
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In February 2022, Russia’s invasion of Ukraine showed that full scale warfare remains a tangible threat even in the twenty first century. The conflict did not end swiftly, rather, it has been reconfigured into a new form of protracted war in which elements of twentieth century full scale warfare, such as trench fighting, artillery duels, and mass mobilization, are fused with twenty first century advanced technologies. The structure of the international order and the transformation of military strategy are being put to the test simultaneously.
Since the end of the Cold War, many states have oriented their military strategies toward local conflicts, irregular warfare, and deterrence rather than full scale war. However, the war in Ukraine shows that this strategic environment has once again reached a turning point. Despite NATO’s eastward expansion, the annexation of Crimea, and the imposition of international sanctions, Russia pressed ahead with a full scale invasion, laying bare the stark reality that deterrence theory alone cannot prevent war 1)
. A crucial point of observation is that this war does not remain confined to a simple military confrontation. Instead, it takes on the characteristics of a “total war,” encompassing non military domains such as energy, logistics, communication infrastructure, financial systems, and public opinion warfare. Ukraine has shifted the entire state to a wartime footing, operating a mobilization system in which the military, the civilian sector, and industry are integrated to sustain the war. 2) . In a highly complex security environment like that of South Korea, where strategic rivalries among neighboring great powers are intensifying, the notion of total war should no longer be regarded as not merely theoretical, but a prerequisite for policy formulation.
Due to its geopolitical characteristics and demographic structure, South Korea is situated in an environment where the prospect of full scale war is inescapable. Accordingly, deterrence strategies must be pursued in parallel with the capacity to sustain protracted conflict, the establishment of a national mobilization system, and a transition to a technology-based defense posture. The Russia–Ukraine War highlights the need for South Korea to prepare proactively and preemptively for a paradigm shift in warfare. -
The patterns of warfare have evolved in accordance with shifts in the dominant killer across historical eras. In antiquity, cavalry and bows served as the dominant killers on the battlefield, while in the modern period, firearms and artillery took over that role. The twentieth century saw the emergence of mass destruction and multidimensional maneuver as defining features of warfare, with artillery, tanks, and aircraft acting as the dominant killers. Since the Cold War, nuclear weapons and precision-guided munitions have shaped a deterrence-centered paradigm of war. In the 2020s, drones and AI-based weapons have emerged as the new dominant killers, driving innovation on the battlefield.
Many strategists and researchers identify the 2020s as the beginning of the era of Automated Warfare. Particular attention should be paid to the fact that low-cost drones and robots are replacing traditional high-cost platforms such as tanks, fighter jets, and helicopters, making human-free battlefields an emerging reality.
The Russia–Ukraine War constitutes a salient example of the actual implementation of Automated Warfare. The Ukrainian military has repurposed commercial drones (e.g., DJI) into FPV-based loitering munitions, carrying out precision strikes on both fixed and mobile targets such as trenches, supply routes, and tanks. Single operators coordinate with artillery units in real time to guide highly accurate fire. Russia, for its part, has deployed Iranian-made Shahed-136 loitering munitions to strike Ukraine’s rear-area energy infrastructure, thereby maximizing both strategic and psychological effects. AI-based video analysis, automated target recognition, and fire control algorithms are accelerating decision-making and shortening the strike loop, while satellite communication systems (e.g., Starlink) and electronic warfare equipment enable the seamless integration and efficient operation of these technologies.
According to Ukrainian sources, more than 80 percent of Russian combat casualties this year were caused by drones, and in May 2024 alone, Ukrainian drones struck approximately 89,000 Russian targets. This demonstrates that drones have evolved beyond the role of reconnaissance assets to become core combat systems that dominate the battlefield. This transformation implies that drone acquisition must be accompanied by innovation in operational concepts and the strengthening of integration with command, control, communications, computers, and intelligence (C4I) systems. The Republic of Korea Armed Forces has established the Drone Operations Command and formulated an unmanned force development plan, yet follow-up measures remain insufficient in several practical areas, including the concretization of operational concepts, munitions employment systems, doctrines for urban warfare, and protection systems against loitering munitions.
In this regard, drones should be regarded not as auxiliary assets but as independent combat entities, and the development of combat-ready doctrines based on MUM-T (Manned-Unmanned Teaming) has become an urgent priority. It is also essential to secure combat drones and ground control systems at an early stage through cooperation with private enterprises, while simultaneously revising relevant legal and institutional frameworks and establishing systems for the training and development of specialized personnel.
Major countries such as the United States, the United Kingdom, and Australia are pursuing the force development of Robotic and Autonomous Systems (RAS) as part of their national-level defense strategies. U.S. Secretary of Defense Pete Hegseth has instructed that, in the Fiscal Year 2026 defense budget, approximately 50 billion dollars be reallocated by reducing acquisitions of existing legacy platforms and redirecting the funds toward investments in AI, drones, and unmanned capabilities. To this end, together with the professionalization of the reserve mobilization system, the following structural transformations are required:
- · Preemptive response to shifts in adversary technologies and tactics
- · Flexible adaptation to rapid changes in the future battlefield environment
- · Enhancement of combat efficiency and force superiority
- · Reduction of soldiers’ exposure to risk and mitigation of physical and cognitive burdens
The Republic of Korea Armed Forces has recently initiated a reassessment of certain conventional force development plans that have traditionally emphasized large-scale platforms. However, such efforts must transcend incremental adjustments and instead be situated within a comprehensive strategic redesign aligned with the anticipated force structure of the 2030s. At this critical juncture, it is imperative to pursue structural innovation that systematically integrates technological advancement, doctrinal evolution, and organizational reform, thereby moving beyond the passive adoption of emerging technologies toward a proactive, future-oriented transformation of military capability. -
Immediately after the outbreak of full-scale war, Ukraine issued a general mobilization order that brought millions of personnel into service. Russia, for its part, has relied on a combination of reserve forces and private military companies (PMCs) to secure the manpower and combat capabilities necessary to sustain the front lines. Notably, Ukraine activated a whole-of-society mobilization system, deploying not only reservists, police units, and civil defense forces, but also older adults over the age of sixty, female volunteers, and civilian professionals to both front-line and rear-area roles. Beyond the mere provision of manpower, the active involvement of technically skilled civilians, including medical personnel, communications specialists, and drone operators, illustrates that in contemporary warfare, the strategic employment of non-standing force resources can serve as a decisive variable in overall force effectiveness.
This experience illustrates that, in the context of protracted wars of attrition or long-term, high-intensity conflicts, a nation's capacity to conduct and sustain war is fundamentally shaped by how organically its wartime mobilization system functions. Reliance on standing forces alone renders it virtually impossible to endure extended hostilities, and the state's ability to sustain military operations over time hinges on the existence of an integrated system that effectively mobilizes reserve forces and civilian resources.
South Korea is confronting structural constraints, including the world’s lowest total fertility rate (below 0.7) and a sharp decline in conscription-eligible manpower, which increasingly undermine its ability to maintain even a 500,000-strong standing force. Under the current force structure and reserve system, it is virtually unfeasible to respond stably to protracted or full-scale conflicts. Accordingly, a paradigm shift is required to redefine reserve forces not as a supplementary component, but as a “wartime core operational force” in wartime.
This requires not only the professionalization of reserve force employment, but also the implementation of the following structural reforms:
- · Legal institutionalization and organizational refinement of a civilian mobilization system to undertake non combat missions including wartime transportation, maintenance, and logistics support
- · Securing civilian professional resources that can be immediately deployed in areas such as drones, communications, cyber, and medical services by strengthening the system of technical specialists based on civilian expertise
- · Establishing national level stockpiles and wartime production systems for expendable combat assets such as artillery ammunition and drones
- · Transforming the combat organization from a soldier based structure into an officer led, unmanned, and AI supported system
In particular, high level wartime missions such as drone operations, long range artillery employment, real time intelligence analysis, and fire coordination cannot be fulfilled through short term instruction alone. To address this, a structured system of recurring proficiency and sustainment training must be institutionalized for reserve officers and civilian professionals. The current mobilization framework remains focused on personnel administration grounded in peacetime convenience, with limited emphasis on combat realistic training or integrated operational exercises under wartime scenarios. This discrepancy creates a growing gap between battlefield mission requirements and the practical capabilities of the reserve force, exposing clear limitations in their operational effectiveness.
Accordingly, going forward, it is necessary to establish legal and institutional foundations that enable the parallel operation of civilian mobilization systems in nonmilitary domains such as cyber, healthcare, information, and technology, along with temporary wartime mobilization plans for nontraditional manpower resources including women and older adults. Moreover, ensuring real time linkage between mobilization and operational command, namely the flexibility and continuity of an integrated operational system based on C4ISR, is a prerequisite for sustaining protracted warfare and enabling the efficient employment of national defense capabilities.
In the end, strengthening reserve forces should not be viewed merely as a remedy for manpower shortages, but rather as a foundational component in the strategic redesign of future military force structure. For South Korea, facing ultra low fertility and demographic decline, the only viable solution to prepare for a protracted conflict lies in establishing a “national wartime total mobilization system” that integrates reservists, civilian experts, and technology based assets. -
Ukraine, as a nonmember state of the North Atlantic Treaty Organization (NATO), has been waging a full scale war without the security guarantees provided by the collective defense commitments of the United States or NATO. This limitation has underscored the inherent constraints of relying on external assistance. Notably, in the second half of 2023, prolonged budget gridlock in the United States Congress resulted in the suspension of military aid to Ukraine for several months. Russia exploited this window of vulnerability as an opportunity to launch intensified offensives. Delays in the delivery of HIMARS, air defense systems, ammunition, and long range strike capabilities significantly impeded Ukraine’s ability to hold key positions on the battlefield, leading to the collapse of portions of the southern defensive lines.
By contrast, the resumption of United States military assistance in early 2024 enabled Ukraine to restore its drone, artillery, and electronic warfare capabilities, thereby allowing it to initiate limited counteroffensives on selected fronts. This case demonstrates that external military support can function as a decisive factor shaping the trajectory of a conflict. At the same time, it highlights the strategic vulnerability embedded in a structure of external reliance, given that the scope and consistency of such support are subject to fluctuations in the United States' domestic politics, public opinion, and its willingness to engage in overseas interventions. 6)
The case of Ukraine carries important implications for South Korea. As a formal ally of the United States, South Korea benefits from the protection of a mutual defense treaty and possesses robust institutional foundations, including the stationing of United States Forces in Korea, the combined operational command system, and the provision of extended deterrence. Nevertheless, the inauguration of a second Trump administration, the rise of isolationist sentiment within the United States, and growing demands for increased defense cost sharing have all intensified doubts regarding the long term reliability of U.S. overseas commitments. Amid such uncertainty, the Korean model of extended deterrence (Extended Deterrence 2.0) must evolve beyond exclusive reliance on the nuclear umbrella and build strategic resilience to ensure credible deterrence.
“Extended Deterrence 2.0” represents a strategic shift away from the passive concept of deterrence that depends solely on the provision of a nuclear umbrella, and toward reinforcing South Korea’s initiative and autonomy within the alliance by expanding its independent capabilities in command and control, intelligence, surveillance and reconnaissance (“C4ISR”), as well as long range precision strike. This constitutes an effort to build “strategic resilience,” ensuring that South Korea can exercise a certain level of deterrent power on its own should the availability of United States strategic assets be constrained in wartime.
Elbridge Colby, the U.S. Under Secretary of Defense for Policy and a key architect of current American defense strategy, remarked in a 2024 interview that “redeploying tactical nuclear weapons does not fundamentally resolve the nuclear and missile threats posed by North Korea,” and further stated that “the United States cannot guarantee the provision of a nuclear umbrella.” He argued that South Korea should consider developing its own nuclear latency or independent deterrence capabilities.7)
In this context, South Korea’s model of extended deterrence must be specified in the following directions:
- · Securing autonomous deterrence by strengthening the ROK military’s C4ISR and precision strike capabilities
- · Redefining the combined command structure in conjunction with the transfer of wartime operational control (OPCON)
- · Formulating mid to long term strategies such as acquiring nuclear latency at the level of Japan or jointly developing nuclear powered submarines
- · Establishing a ROK–U.S. joint response manual and automatic response protocols in times of crisis to prepare for uncertainties in U.S. intervention
To enable such a strategic transformation, it is essential to simultaneously pursue the modernization of air bases, expansion of infrastructure for F35A missions, establishment of standards for nuclear weapons storage and management, integration of the C4ISR system, enhancement of defense space capabilities, and advancement of joint planning and training between South Korea and the United States. In parallel, strategic communication efforts are necessary to foster public consensus. Rather than relying solely on security based logic, this must be implemented as part of a comprehensive national strategy aligned with three key objectives: preparation for future warfare, prioritization of national interests, and the attainment of autonomous deterrence capabilities.
Ultimately, it must be recognized that strengthening autonomy within the framework of the alliance is a key means of enhancing the credibility of deterrence, and that it is the path to securing both survival and leadership in the uncertain security environment of the future. -
The Russia–Ukraine war has shown that even in the twenty-first century, full-scale war is a real threat, and that the nature of warfare is evolving into a form of total war where technology, manpower, and alliances interact in complex ways. This war calls for a fundamental reexamination of the three foundations of South Korea’s security strategy.
First, the essence of the battlefield lies not in technology itself, but in the integration of operational concepts and force employment systems that make use of it. Drone and AI based weapons are not simply pieces of equipment, but tools that fundamentally transform the way wars are fought. The ROK Armed Forces must urgently pursue integrated innovation that spans not only the adoption of technology, but also operational concepts, legal and institutional frameworks, and personnel systems.
Second, the core of a sustainable force structure lies in the actual militarization of reserve forces. Under a low birthrate structure, maintaining large standing forces faces structural limitations, and there is an urgent need for a whole-of-society mobilization system to prepare for wartime total war. Priority tasks include the professionalization of reservists, the integration of civilian expertise into operational systems, and the institutionalization of nontraditional manpower resources.
Third, a transition is required from a deterrence strategy dependent on the alliance to one based on autonomous deterrence. As Elbridge Colby, the U.S. Under Secretary of Defense for Policy, pointed out, the redeployment of tactical nuclear weapons or the credibility of the nuclear umbrella may be constrained by political changes in the United States. This suggests that South Korea must acquire independent nuclear latency, surveillance and reconnaissance, and precision strike capabilities. To secure survival and leadership in an uncertain international order, South Korea must possess “strategic resilience” that can compensate for the limitations of alliance-based deterrence.
South Korea’s security strategy must now evolve beyond the mere acquisition of military capabilities into a “practical national total war system” in which technology, organizational structures, and the civilian population are organically connected. Civil–military integrated training, response scenarios for cyber and psychological warfare, emergency infrastructure backups, and wartime industrial conversion go beyond simple crisis management and instead form the essential foundations of deterrence.
In the end, deterrence is not just a matter of military power. When sober recognition of reality is combined with institutional flexibility, technological innovation, and public consensus, South Korea can establish itself as a nation trusted for both its credibility and capability to prevent war.
| Preface
1) Michael Kofman and Rob Lee, "Not Built for Purpose: The Russian Military's Ill-Fated Force Design," War on the Rocks, 2022.3.2.
2) 허광환, “러시아-우크라이나 전쟁 1년이 한반도 미래전에 주는 함의”, 『한국군사』 제13권, 2023, pp. 57-88.
| Technological Transformation and Innovation in Warfare
3) Williamson Murray and MacGregor Knox (eds.), The Dynamics of Military Revolution: 1300–2050, 2001.
4) CSBA, Weapon of Mass Disruption, 2023.
5) Michael Horowitz, The Diffusion of Military Power, 2010.
| Force Structure for Protracted Warfare
| Balancing Alliances and Independent Deterrence
6) Riley Bailey and Frederick W. Kagan, "Russian Offensive Campaign Assessment, March 15, 2024," Institute for the Study of War(ISW)
7) 엘브리지 콜비, “핵우산은 보장할 수 없다…한국, 자체 핵무장 고려해야,” 중앙일보 인터뷰 (2024.4.25), “전술핵 재배치는 북한 ICBM을 막지 못한다,” 연합뉴스 인터뷰 (2024.5.8).
| Conclusion: Deterrence and Strategies for Protracted Warfare in the Era of Total War
※ The contents published on 'Sejong Focus' are personal opinions of the author and do not represent the official views of Sejong Institue
