How to cite this article / Come citare questo articolo
Rudro, M. T. U. (2026). Reassessing the Classification of Armed Conflicts in Contemporary Warfare. Aequitas Magazine, 5, 46-52.
DOI: https://doi.org/10.5281/zenodo.20022295
ABSTRACT (EN) This article critically reassesses the adequacy of the traditional dichotomy between international armed conflicts (IACs) and non-international armed conflicts (NIACs) in light of the evolving nature of contemporary warfare. The emergence of hybrid conflict patterns – characterized by indirect state intervention, cross-border operations, and the increasing involvement of non-state actors – has progressively undermined the classificatory capacity of the binary framework of international humanitarian law (IHL), generating legal uncertainty and inconsistent application. The study adopts a doctrinal and jurisprudential approach, drawing on treaty law, customary international law, and international case law, with particular emphasis on the “effective control” test developed by the International Court of Justice and the “overall control” standard elaborated by the International Criminal Tribunal for the former Yugoslavia. It identifies persistent ambiguities in the criteria governing conflict classification and the thresholds for internationalization. The analysis is supported by selected case studies (Syria, the Democratic Republic of the Congo, and Ukraine), which illustrate how the coexistence of international and non-international elements leads to fragmentation in the applicable legal regimes. The article argues that, while the IAC–NIAC dichotomy should not be abandoned, it requires substantial interpretative refinement. It advances the need for more structured and operational criteria for classifying hybrid conflicts and suggests the adoption of graduated classificatory models capable of enhancing legal certainty and ensuring more consistent humanitarian protection.
ABSTRACT (IT) Il contributo analizza criticamente l’adeguatezza della tradizionale dicotomia tra conflitti armati internazionali (IAC) e non internazionali (NIAC) alla luce delle trasformazioni della guerra contemporanea. L’emergere di forme ibride di conflitto, caratterizzate da interventi indiretti di Stati, operazioni transfrontaliere e coinvolgimento di attori non statali, ha progressivamente eroso la capacità classificatoria del modello binario del diritto internazionale umanitario (DIU), generando incertezza normativa e applicativa.Attraverso un’analisi sistematica del diritto convenzionale, del diritto internazionale consuetudinario e della giurisprudenza internazionale – con particolare riferimento agli standard di “effective control” della Corte internazionale di giustizia e di “overall control” del Tribunale penale internazionale per l’ex Jugoslavia – lo studio evidenzia le persistenti ambiguità nei criteri di qualificazione dei conflitti e nelle soglie di internazionalizzazione. L’indagine è corroborata da un’analisi di casi emblematici (Siria, Repubblica Democratica del Congo, Ucraina), nei quali la coesistenza di elementi internazionali e non internazionali produce una frammentazione dei regimi giuridici applicabili. Il contributo sostiene che il mantenimento della dicotomia IAC/NIAC rimane funzionale sul piano sistematico, ma richiede un significativo affinamento interpretativo. In questa prospettiva, si propone lo sviluppo di criteri più strutturati e operativi per la qualificazione dei conflitti ibridi, nonché l’adozione di modelli classificatori graduati idonei a garantire maggiore certezza del diritto e uniformità nella protezione umanitaria.
SUMMARY: 1. Introduction – 2. IHL – 3. Case Studies – 4. Conclusion.
1. Introduction
IHL regulates armed conflicts with the principal aim of safeguarding individuals who are not involved, or who have ceased involvement, in hostilities. They set up different rules for IACs & NIACs. This traditional binary classification has long been considered essential for determining the applicability of legal rules and the extent of humanitarian protection during armed conflict. but the changing nature of war has made this strict division less useful.
Modern armed conflicts rarely resemble the classical interstate wars envisioned by the drafters of the Geneva Conventions. Cross-border military operations, indirect foreign interventions, and hybrid forms of warfare that combine international and internal elements. As a result, the distinction between IACs and NIACs has become blurred, making conflict classification a legally complex and contested exercise. Although IHL formally recognizes only these two categories, many present-day conflicts do not fit neatly within either framework, creating uncertainty in the humanitarian norms.
The classification of an armed conflict is not merely a theoretical issue but carries significant legal and practical consequences. Determining whether a conflict qualifies as an IAC or a NIAC dictates which body of IHL applies and, consequently, the level of protection afforded to victims. IACs are governed by an extensive treaty framework, including the full scope of the Geneva Conventions. This disparity means that uncertainty or misclassification may result in reduced legal protections and operational ambiguity for those tasked with applying IHL in real time.
In this context, the classification of armed conflict has become increasingly problematic in modern warfare. The evolving nature of hostilities challenges the adequacy of the traditional IAC–NIAC dichotomy and raises questions about whether existing legal frameworks remain fit for purpose. This dissertation critically examines these challenges, analyzing the legal criteria for conflict classification and the consequences arising from contemporary forms of warfare. By doing so, it seeks to assess whether reinterpretation or reform of the existing classification system is necessary to preserve the humanitarian objectives of IHL.
2. IHL
IHL, which aims to control hostilities and safeguard those who are not or are no longer involved in armed conflict, is the main source of the legal framework governing armed conflict. The four Geneva Conventions of 1949, their Additional Protocols of 1977, & principles of customary international humanitarian law form the foundation of this framework. The classification of the armed conflict as either an IAC or NIAC is a crucial factor in determining the applicability and scope of these legal instruments.
2.1. IACs
The most extensive body of IHL governs international armed conflicts. Regardless of whether one party acknowledges the state of war, an IAC is created under Common Article 2 of the Geneva Conventions whenever there is a declared war or “any other armed conflict” between two or more High Contracting Parties.¹ Since neither the severity nor the length of hostilities are legally significant, there is a very low threshold for the existence of an IAC. The application of the Geneva Conventions may be triggered by even brief or infrequent uses of armed force between states.
The protection provided to victims of international armed conflicts is further elaborated by Additional Protocol I (1977). Crucially, military occupation scenarios are also classified as IACs, even in the absence of armed opposition, guaranteeing ongoing legal protection for the occupied civilian population.
2.2. NIACs
In contrast, NIACs are subject to a far more constrained legal framework. Common Article 3 of the Geneva Conventions, which covers “armed conflict not of an international character occurring in the territory of one of the High Contracting Parties,” provides NIACs with the minimal level of protection.
Additional Protocol II (1977) expands the scope of NIAC regulation by limiting its application to situations in which organized armed groups or dissident armed forces, under responsible command, have sufficient control over a portion of a state’s territory to carry out persistent and well-coordinated military operations. Common Article 3 and customary IHL are the main sources of law in many modern conflicts because Additional Protocol II’s higher threshold makes it inapplicable.
International jurisprudence, particularly the Tadić case before the ICTY, has clarified the definition and identification of NIACs. According to the Appeals Chamber, “prolonged armed violence between governmental authorities and organized armed groups or between such groups within a State” constitutes an NIAC. The organization of the armed groups and the level of hostilities were introduced as two cumulative criteria in this formulation.
2.3. Internationalized and Hybrid Conflicts
Modern armed conflicts frequently blur the traditional distinction between IACs and NIACs, particularly where foreign States intervene in internal conflicts by supporting non-State armed groups. In such situations, determining the applicable legal framework becomes highly contested. International jurisprudence has attempted to address this problem through attribution tests, most notably in the Nicaragua case, where the ICJ adopted the “effective control” test to determine State responsibility for the acts of armed groups.⁹
Conversely, the ICTY in Tadic advanced the “overall control” test, lowering the threshold for internationalization of a conflict where a foreign State exercises a sufficient degree of control over an armed group.¹⁰ the coexistence of these competing standards has generated legal uncertainty and practical difficulties.
3. Case Studies
3.1. The Syrian Conflict
The Syrian conflict illustrates the complexities of classifying contemporary armed conflicts. Initially characterized as a non-international armed conflict between the Syrian government and various organized armed groups, the conflict later involved multiple foreign states conducting military operations within Syrian territory. These interventions created parallel legal regimes, with some hostilities qualifying as IACs between states and others remaining NIACs.
The simultaneous application of different legal classifications generated uncertainty regarding the applicable rules and accountability mechanisms. Humanitarian organizations faced challenges in determining the legal framework governing their operations, while courts struggled to apply consistent standards of responsibility.
3.2. Democratic Republic of the Congo
The conflict in the Democratic Republic of the Congo (DRC), particularly during the Second Congo War (1998–2003) and its prolonged aftermath, represents one of the most legally complex cases of conflict classification in recent international law. Numerous armed groups operated across Congolese territory with varying degrees of external support from neighboring states, including Rwanda, Uganda, and Burundi, all of which deployed regular armed forces within DRC borders at different stages of the conflict. This direct military involvement raised fundamental questions about whether the hostilities should be classified as an IAC—given the presence of foreign state forces—or a NIAC, given that much of the fighting involved non-state armed groups such as the Forces Démocratiques de Libération du Rwanda (FDLR) and the Mouvement du 23 Mars (M23).
Legal debates focused centrally on whether external state support amounted to sufficient control to internationalize the conflict under the competing standards established in Nicaragua and Tadić. The International Court of Justice, in Armed Activities on the Territory of the Congo (DRC v Uganda, 2005), held Uganda responsible for acts of its armed forces and for failing to prevent violations committed by armed groups under its control. However, the Court stopped short of applying the overall control test, relying instead on direct attribution for the conduct of Ugandan military forces. This divergence from the ICTY’s broader approach further deepened doctrinal inconsistency.
Inconsistent application of control tests resulted in significant ambiguity and uneven protection for affected populations. Humanitarian organizations operating in the DRC faced uncertainty as to which legal framework governed their activities and which obligations bound the parties to the conflict. The DRC experience thus highlights a structural limitation of the existing classification framework: when international judicial bodies apply different attribution standards, the protective function of IHL is undermined, and accountability for violations becomes procedurally fragmented across multiple legal regimes.
3.3. Russia–Ukraine Conflict
The conflict between Russia & Ukraine, particularly since 2014, exemplifies the challenges posed by hybrid warfare. The use of unmarked troops, denial of direct involvement, and support for separatist forces blurred the distinction between IAC and NIAC. Despite evidence of foreign military participation, classification remained contested for a significant period.
This uncertainty delayed legal clarity and accountability and highlighted the inadequacy of existing thresholds for addressing modern conflict realities.
3.4 Consequences of Misclassification
The case studies examined above are not merely academic exercises: the classification decisions made in Syria, the DRC, and Ukraine produced direct legal effects for those affected by hostilities. Misclassification of armed conflicts carries significant legal, humanitarian, and operational consequences. When an armed conflict is incorrectly categorized, the applicable rules of IHL may be misapplied, resulting in gaps in protection for civilians, combatants, and other affected individuals. For instance, NIACs are governed by more limited provisions than IACs, meaning that misclassifying a hybrid or internationalised conflict as a NIAC could deny parties the broader protections guaranteed under IAC regulations, such as those concerning prisoners of war or the use of certain weapons. Conversely, incorrectly treating a NIAC as an IAC may impose obligations on non-state actors that are impractical or unenforceable, complicating compliance and accountability. Operationally, misclassification can generate confusion for military commanders, who may struggle to implement the correct targeting protocols, leading to unintended civilian casualties and violations of humanitarian law. Politically, misclassification may also affect international responses, such as sanctions, foreign interventions, or recognition of belligerent parties, thereby exacerbating conflict dynamics and undermining conflict resolution. Moreover, at the judicial level, courts and tribunals may face difficulties in adjudicating responsibility and enforcing legal norms, particularly in complex hybrid conflicts where both international and non-international elements coexist. Collectively, these consequences underscore the critical need for accurate conflict classification to uphold the protective and regulatory objectives of IHL while reducing ambiguity for states, armed groups, and the international community.
4. Conclusion
The analysis of contemporary armed conflicts underscores the urgent need for a reassessment of the traditional IAC-NIAC dichotomy. Modern warfare, exemplified by the conflicts in Syria, the Democratic Republic of Congo, & Ukraine, demonstrates that armed engagements increasingly involve hybrid and internationalized elements, blurring the lines between conventional international & non-international armed conflicts.
One key recommendation is the development of clearer guidelines for identifying and classifying hybrid conflicts. This includes establishing objective criteria for foreign state involvement in non-international armed conflicts, particularly in cases of proxy warfare, to determine when such conflicts should be internationalized. The creation of a standardized assessment framework would enable states, courts, and international organizations to apply International Humanitarian Law (IHL) consistently, thereby reducing ambiguity and enhancing protection for affected populations.
Finally, scholars and policymakers should examine the potential of introducing a third category or tiered classification of armed conflicts to better reflect the realities of modern warfare. This proposal is not novel: James G. Stewart and Robert Kolb have both argued that the binary IAC–NIAC framework fails to accommodate the full spectrum of contemporary hostilities, while Marco Sassòli has suggested that a more graduated approach to IHL applicability—one sensitive to the degree of foreign state involvement and the organizational capacity of non-state actors—could resolve many of the ambiguities identified in this paper. A tiered model might, for instance, establish an intermediate category for internationalized NIACs in which a defined set of IAC rules, such as those governing prisoner of war status and civilian internment, applies automatically once a threshold level of foreign state control over an armed group is established. Such a category would not require abandoning the existing dichotomy but would supplement it, providing greater legal certainty for humanitarian actors, military commanders, and courts without imposing unenforceable obligations on parties ill-equipped to comply with the full IAC regime.
In conclusion, the dissertation demonstrates that the classification of armed conflicts in modern times is complex and evolving. Traditional dichotomies often fail to capture the nuanced nature of hybrid conflicts, internationalization, and transnational interventions. Legal ambiguities surrounding the timing, intensity, and foreign involvement in conflicts impede consistent application of IHL.
References
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