Defining the Indefinable: A Critical Analysis of Current Irregular Warfare Doctrine

By Duc DuClos

“The beginning of wisdom is the definition of terms.” — Socrates

“Precision of language leads to precision in thought.” — Anonymous

Introduction

On November 1st, 2024, the Army University Press YouTube channel released a comprehensive examination of irregular warfare doctrine. This professionally produced video, part of the Combined Arms Doctrine Directorate's ongoing doctrinal review, weaves together combat footage, historical imagery, and dynamic graphics with insights from academic scholars, military practitioners, and senior leaders. While presenting an authoritative view of irregular warfare's doctrinal evolution, the video inadvertently demonstrates the SOF community's broader challenges in conceptualizing this complex form of conflict. Through its attempt to capture every aspect of irregular warfare, the video reflects the current definitional challenges facing military doctrine writers and practitioners.

The video's examination begins with Clausewitz's enduring principle that "the character and form of war are constantly changing, yet its fundamental nature remains the same." This observation proves particularly relevant as the U.S. military adapts irregular warfare capabilities—honed through two decades of counterterrorism operations—to address Great Power Competition. However, the video's subsequent attempts to define irregular warfare reveal definitional challenges shared by current joint doctrine, suggesting systemic issues in how the military conceptualizes irregular warfare. These challenges extend beyond mere terminology to fundamental questions about the nature of irregular warfare itself.

The term "irregular warfare" has undergone a significant transformation, evolving from a straightforward descriptor of warfare conducted by irregular forces to an increasingly complex doctrinal concept. This evolution mirrors broader changes in military thinking, where simple descriptive terms often evolve into technical concepts laden with specific requirements and restrictions. The video demonstrates how this transformation, while attempting to add precision, often achieves the opposite effect—creating confusion rather than clarity.

This pattern reveals a fundamental challenge in military theory: the tendency to substitute detailed description for clear definition. As Clausewitz reminds us, doctrine should guide judgment rather than replace it. Yet current doctrinal attempts, exemplified both in the video and recent joint publications, risk undermining the concept's utility by simultaneously broadening its scope while constraining its application through arbitrary requirements and restrictions.

The video's definitional struggles mirror broader doctrinal challenges facing the military community. Both the video and current joint doctrine demonstrate a pattern of accumulating descriptive characteristics and operational restrictions rather than providing clear definitional differentiation. Through examining the parallel evolution of irregular and guerrilla warfare concepts, and analyzing various definitional approaches through classical definitional theory, this analysis reveals how current attempts to define irregular warfare have created a paradox that undermines both theoretical understanding and practical application.

Theoretical Framework: Understanding Definition

Classical definitional theory provides essential analytical tools to evaluate various irregular warfare definitions, including those presented in recent doctrine and the Army University Press video. Aristotle's approach to definition, outlined in Categories and Topics, requires two components: genus (the broader category to which something belongs) and differentia (the specific characteristics that distinguish it from other members of that category). This framework reveals how military definitions often describe rather than define concepts, particularly in attempts to characterize irregular warfare.

Early understandings of irregular warfare demonstrated this Aristotelian clarity. They established warfare as the genus and the relationship between actors—specifically the involvement of non-state participants or irregulars—as the key differentia. This actor-centric differentiation provided clear delineation: conventional warfare occurred between state actors, while irregular warfare involved at least one non-state participant. Contemporary conflicts illustrate the enduring relevance of this distinction, as seen in Ukraine where resistance forces maintain their irregular character despite operating alongside state military forces in territorial defense.

The evolution away from this clear framework has produced several distinct approaches to defining irregular warfare. These approaches, while attempting to capture modern operational complexity, often fail to meet basic definitional requirements. Most current attempts, including those presented in the video and joint doctrine, either lack proper differentia (failing to distinguish irregular warfare from other forms of warfare) or improperly restrict the concept through artificial limitations. This pattern creates particular challenges for SOF practitioners developing partner nation resistance capabilities, where clear conceptual understanding proves crucial for effective operational implementation.

Historical Evolution and Semantic Drift

The semantic evolution of irregular warfare parallels that of guerrilla warfare, a comparison that reveals crucial insights into how military concepts drift from their original meanings. Both terms initially described warfare based on the nature of its participants rather than their methods. The term "guerrilla warfare" emerged from the Peninsular War (1808-1814), derived from the Spanish "guerra" meaning war, and "ilia," meaning small—a straightforward description of warfare conducted by small, irregular forces.

Historical documents reveal the clarity of this actor-based understanding. British officers serving with Spanish irregulars consistently used "guerrilla" to describe the fighters themselves, not their tactics. During the American Revolution, period documents described Francis Marion's forces as "partisan forces" or "irregular troops," though they employed what modern doctrine would call "irregular tactics." The Boer War (1899-1902) correspondence similarly emphasized the irregular status of Boer commandos rather than their methods. This actor-centric understanding maintains relevance today, as demonstrated by resistance movements that retain their irregular character despite employing diverse tactical approaches.

The conceptual transformation began in the early 20th century through influential theorists who systematized irregular warfare approaches. T.E. Lawrence's Arab Revolt experiences, documented in "Seven Pillars of Wisdom" (1926), demonstrated how conventional forces could adopt irregular methods. Mao Zedong's "On Guerrilla Warfare" (1937) further shifted focus from actors to methods, presenting guerrilla warfare as a tactical system available to any force. These works initiated a conceptual shift that accelerated through subsequent decades, contributing to current definitional challenges.

The post-World War II period marked a crucial doctrinal transition. While early military publications maintained some actor-based distinction, terminology increasingly emphasized methods over participants. This evolution continues in current doctrine and the recent Army University Press video, which define irregular warfare through methods, purposes, and effects rather than by its participants. This shift mirrors contemporary challenges in partner nation development, where practitioners must balance traditional resistance capabilities with modern operational requirements.

This semantic drift from clear actor-based definition to various method-based approaches has produced several competing definitional frameworks, each revealing different aspects of the challenge. As demonstrated in both current joint doctrine and the Army University Press video, these approaches often create more confusion than clarity, failing to provide clear delineation while simultaneously restricting operational utility.

Approaches to Defining Irregular Warfare: A Critical Analysis

The evolution of irregular warfare concepts has produced several distinct definitional approaches, each revealing different aspects of this complex challenge. The recent Army University Press video and current joint doctrine exemplify these approaches, demonstrating how well-intentioned attempts to capture modern operational complexity often create more problems than they solve. When examined through Aristotelian definitional theory, each approach fails to provide the clear differentiation necessary for proper definition.

The Doctrinal Authority Approach (Doctrine as Dogma)

The most problematic definitional attempt relies on circular logic: something is true simply because doctrine says so. Both the video and current joint publications exemplify this when asserting that irregular warfare must include "indirect, non-attributable, or asymmetric activities" solely because doctrine mandates these characteristics. While doctrine provides essential guidance, treating it as infallible creates a logical fallacy of appeal to authority. As seen in current resistance operations in Ukraine, effective irregular warfare often defies such doctrinal restrictions.

The Semantic Expansion Approach (The Adjective Problem)

This approach attempts to define irregular warfare by liberally applying "irregular" as a modifier to various military concepts. Current doctrine and the video demonstrate this tendency through references to irregular operations, activities, approaches, effects, capabilities, and even irregular warfare campaigning. This linguistic expansion creates meaningless terminology - what exactly makes an operation or effect "irregular"? The approach shifts the definitional problem without solving it, complicating rather than clarifying the concept.

The Universal Inclusion Approach (The Kitchen Sink)

Current joint doctrine and the video demonstrate a tendency to treat irregular warfare as a catch-all term encompassing virtually every military activity outside large-scale combat operations. This approach sweeps in information operations, cyber operations, human domain operations, space operations, and various special operations missions under the irregular warfare banner. The definition expands further to include any activity that assures partners or coerces adversaries. This approach violates basic logic - if irregular warfare includes everything, it effectively means nothing. Recent Baltic and Nordic defense preparations demonstrate this problem, where the overly broad definition of irregular warfare complicates rather than clarifies resistance planning.

The Methodological Dichotomy Approach (Direct versus Indirect)

This approach creates an artificial distinction between irregular warfare's supposedly indirect methods and conventional warfare's direct approaches. Such categorization ignores operational reality. Operation Desert Storm, while featuring direct force-on-force engagements, relied heavily on indirect psychological effects. Conversely, irregular forces often engage in direct tactical actions. Ukraine's territorial defense forces exemplify this, conducting both direct defense of territory and indirect resistance activities. Successful operations employ whatever methods circumstances require, regardless of doctrinal categorization.

The Target Differentiation Approach (Population-Centric)

The attempt to differentiate irregular warfare through its focus on populations versus military forces fails under both historical and contemporary scrutiny. Conventional warfare has long targeted civilian populations to affect enemy decision-making, from World War II strategic bombing to modern Russian operations in Ukraine. Meanwhile, irregular forces frequently focus on military targets. This approach creates a false dichotomy that neither reflects historical experience nor serves current operational needs in developing partner nation resistance capabilities.

The Temporal Prevalence Approach (Frequency and Gray Zone)

Some attempts to define irregular warfare focus on its temporal characteristics - either its frequency or its place in the competition continuum. The video echoes Max Boot's observation that "irregular warfare happens more regularly than regular warfare," yet even Boot maintained an actor-based definition rather than defining through frequency. Similarly flawed is the attempt to restrict irregular warfare to "gray zone" activities before conventional conflict. Modern conflicts demonstrate that regular and irregular warfare often occur simultaneously - from Vietnam's parallel conventional and unconventional campaigns to Ukraine's current integration of resistance operations with conventional defense. Temporal characteristics cannot define warfare's fundamental nature.

The Operational Characteristics Approach (Methods-Based)

The attempt to define irregular warfare through specific techniques like indirect action, asymmetric warfare, or information operations fundamentally misunderstands the nature of warfare itself. These methods appear throughout military history in clearly conventional conflicts. Current doctrine's emphasis on "asymmetric" approaches particularly fails logical scrutiny - the notion of truly symmetric warfare represents a theoretical impossibility. From ancient battles to modern hybrid threats, warfare inherently involves exploiting or managing asymmetries. The methods employed flow from the nature of the actors involved, not vice versa.

The Effects-Based Definitional Approach (Contextual Purpose)

The most recent doctrinal attempt defines irregular warfare through intended effects - to assure partners or coerce adversaries. This definition fails basic logical scrutiny as these purposes characterize all military activities. Conventional deterrence assures allies and coerces adversaries; diplomatic efforts serve the same purposes. Current support to Ukraine's territorial defense and resistance capabilities demonstrates how both regular and irregular operations serve these purposes. Effects cannot differentiate irregular warfare from other military or diplomatic activities.

Analysis of Current Joint Doctrine Definition and Description

While the Army University Press video attempts to clarify irregular warfare doctrine, it instead reflects fundamental definitional issues pervading current military thought. Joint Publication 1 Chapter II exemplifies these challenges, incorporating multiple problematic approaches while adding restrictive requirements. The latest Joint definition, dedicating 614 words to irregular warfare, demonstrates a paradoxical approach - simultaneously too broad in scope yet too restrictive in application.

Base Definition and Initial Description Analysis

The chapter opens with irregular warfare as:

 "a form of warfare where states and non-state actors campaign to assure or coerce states or other groups through indirect, non-attributable, or asymmetric activities, either as the primary approach or in concert with conventional warfare."

This definition immediately incorporates several problematic approaches previously identified.

The Effects-Based Approach appears in the focus on activities that "assure or coerce" - characteristics common to all military operations. The Universal Inclusion Approach manifests in encompassing all activities by "states and non-state actors," while the Semantic Expansion Approach emerges in descriptions of warfare that "seeks to create dilemmas and increase risks." None of these characteristics distinguish irregular from regular warfare.

Most significantly, the definition mishandles actor relationships by suggesting irregular warfare is defined by who can conduct it rather than by the relationship between primary belligerents. Recent operations in Ukraine illustrate this confusion - while both state and non-state actors conduct operations, their relationship to their opponent in the conflict defines whether warfare is regular or irregular, not merely their presence.

The Three Variables: Compounding Definitional Problems

Additionally, JP1 introduces three "essential characteristics" of irregular warfare - indirect, non-attributable, or asymmetric activities. Rather than clarifying the concept, these variables add layers of logical contradiction while demonstrating multiple problematic approaches previously identified.

The treatment of "indirect activities" exemplifies the Methodological Dichotomy Approach, attempting to distinguish irregular warfare through intermediary operations. However, conventional forces routinely use direct and indirect approaches. Current Ukrainian conventional operations demonstrate this overlap – both regular and irregular forces employ direct and indirect methods based on operational requirements, not doctrinal categorization.

The "non-attributable activities" requirement creates perhaps the most glaring contradiction. By defining irregular warfare through activities that "conceal the source or sponsorship," this restriction creates an immediate paradox - how can a published doctrinal concept require non-attribution? This requirement also contradicts historical and contemporary practice, from openly acknowledged support to the French Resistance to current territorial defense preparations in Baltic nations.

The "asymmetric activities" characteristic reveals the Operational Characteristics Approach's fundamental flaw. While the chapter initially ties asymmetry to power disparity between actors, it then acknowledges that stronger parties may also employ asymmetric approaches. This admission effectively negates asymmetry as a differentiating characteristic - if both strong and weak forces employ asymmetric approaches, how does this distinguish irregular from regular warfare?

Institutional Requirements and Contradictions

The chapter on IW concludes with an institutional requirement that appears driven more by organizational equity than operational reality: "All IW operations and activities require conventional force lead, facilitation, or participation." This mandate contradicts both historical evidence and the chapter's own acknowledgment that non-state actors conduct irregular warfare. More importantly, it demonstrates how the current doctrine has moved from defining irregular warfare to describing it and even prescribing its execution, conflating conceptual understanding with operational requirements.

Compounding Problems and Practical Implications

The JP1 chapter's attempt to define irregular warfare through layered descriptions and requirements creates cascading contradictions undermining its practical utility. These contradictions manifest both within individual sections and across doctrinal guidance as a whole.

The campaign planning guidance particularly exemplifies these contradictions. While mandating integration with "broader, long-term USG effort across relevant instruments of national power," the chapter simultaneously directs proactive operations to "deny access or create dilemmas for an opponent's government." This creates fundamental confusion about whether irregular warfare requires comprehensive government integration or permits independent military operations. Current resistance preparation efforts in partner nations highlight this tension as practitioners balance whole-of-government approaches with tactical resistance requirements.

The chapter's treatment of objectives further demonstrates these contradictions. It states that irregular warfare aims to "erode an adversary's legitimacy and influence over a population and exhaust its political will—not necessarily to defeat its armed forces." Yet it later prescribes using irregular warfare to "deter, delay, disrupt, or degrade opponents," suggesting direct military objectives. This confusion about fundamental purposes complicates both doctrinal development and operational planning.

The Need for Clear Delineation

The analysis of Joint Publication 1 reveals a fundamental problem in current military thinking: the attempt to define a concept through accumulated characteristics and restrictions rather than clear differentiation. This approach, reflected in both doctrine and the Army University Press video, has produced guidance that fails to define while over-prescribing operational requirements.

The current treatment particularly fails by mishandling the relationship between state and non-state actors. By stating that irregular warfare can be conducted "BY states and non-state actors" rather than focusing on the relationship BETWEEN primary belligerents, the definition loses the essential characteristic that historically provided clear differentiation. Contemporary resistance operations demonstrate why this distinction matters - the presence of state forces supporting irregular warfare does not transform it into conventional warfare.

The Actor-Based Solution (Participant Differentiation Approach): Return to Logical Foundation

The clearest and most logically sound approach defines irregular warfare based on the relationship between its primary belligerents: state-versus-state conflict represents conventional or regular warfare. In contrast, the conflict between state and non-state or irregular actors represents irregular warfare. This approach satisfies Aristotelian definitional requirements by providing both genus (warfare) and differentia (the nature of the primary opposing forces). Importantly, this represents a return to the original historical understanding of irregular warfare - warfare conducted by "irregulars" - before semantic drift, similar to what occurred with the term guerrilla warfare, began adding layers of complexity and confusion to the concept.

This definitional clarity extends beyond simple categorization. The fundamental relationship between state and non-state actors naturally drives many characteristics commonly associated with irregular warfare, from asymmetric capabilities to indirect approaches. However, these characteristics emerge as natural consequences of the actor relationship rather than defining requirements. Baltic resistance preparations demonstrate this principle - the methods and approaches flow from the irregular nature of the forces involved, not from doctrinal prescriptions.

Importantly, this actor-based definition focuses on the primary belligerents in the conflict - the main opposing forces. The presence of supporting state forces conducting Foreign Internal Defense (FID) or Unconventional Warfare (UW) does not change the fundamental nature of the conflict. State forces supporting an irregular force against another state in UW are participating in irregular warfare; they are not making it conventional warfare. Similarly, state forces supporting another state against irregular forces in FID are participating in irregular warfare; their presence does not change the basic nature of the conflict between state and irregular forces.

This definitional approach provides clear analytical utility while accommodating the complex reality of modern conflicts with multiple supporting actors. It allows partners to develop comprehensive resistance frameworks without artificial doctrinal constraints. Most importantly, it provides military practitioners with a clear foundation for understanding and conducting irregular warfare operations, which is particularly vital as partner nations develop whole-of-society defense and resistance programs.

Implications for Military Theory and Practice

The return to an actor-based definition of irregular warfare carries significant implications for military doctrine, planning, and operations. Unlike the current doctrinal approach that simultaneously tries to include everything while restricting execution, an actor-based definition provides clear delineation while maintaining operational flexibility.

First, this approach eliminates the need for arbitrary restrictions on methods or requirements for specific force participation. The natural dynamics of state versus non-state conflict drive operational approaches based on tactical and strategic necessity rather than doctrinal mandate. This clarity particularly benefits partner nations developing resistance capabilities, allowing them to focus on effective irregular warfare methods without artificial constraints.

Second, understanding irregular warfare through the lens of primary belligerents helps practitioners focus on developing essential partner relationships and building holistic defense and resistance capabilities. This becomes particularly important as partner nations develop whole-of-society approaches to national defense. The Nordic total defense concept and Baltic resistance preparations demonstrate how clear conceptual understanding enables effective integration of population-based capabilities alongside conventional forces.

Conclusion

The evolution of irregular warfare's definition reflects broader changes in military understanding, but current attempts to be inclusive while remaining distinctive create significant conceptual challenges that undermine utility. The recent Army University Press video and current Joint doctrine exemplify these challenges, demonstrating how attempts to precisely define irregular warfare through methods, characteristics, and restrictions result in logical contradictions and practical limitations.

The solution lies in returning to first principles: warfare as the genus and the relationship between primary belligerents as the differentia. This actor-based definition - that irregular warfare occurs between state and non-state actors - provides clear delineation while maintaining operational flexibility. Contemporary resistance operations demonstrate the enduring validity of this approach, as it accommodates modern operational complexity while maintaining conceptual clarity.

Military theorists and practitioners must consider whether maintaining increasingly complex definitions serves strategic thinking, or whether returning to simpler, clearer conceptual frameworks better captures operational reality. Without clear delineation, irregular warfare becomes indistinguishable from warfare itself, losing its value as a distinct concept. Current doctrine's qualifying characteristics and arbitrary requirements further limit the concept without adding meaningful specificity.

The challenge of defining irregular warfare has broader implications for future doctrine development. As the joint force continues to evolve and adapt to changing operational environments, clear and logically sound definitions become increasingly crucial. Rather than attempting to create all-encompassing definitions that try to capture every aspect of a concept, future doctrine might benefit from more focused definitions that clearly delineate distinct phenomena while providing the operational flexibility needed to address emerging challenges.

References

Doctrine

Department of the Army. Army Doctrine Publication 3-0: Operations. Washington, DC: Department of the Army, 2019.

Joint Chiefs of Staff. Joint Publication 1, Volume 1: Joint Warfighting. Washington, DC: Department of Defense, August 2023.

Joint Chiefs of Staff. Joint Publication 3-05: Special Operations. Washington, DC: Department of Defense, 2023.

Books

Aristotle. "Categories and Topics." In The Complete Works of Aristotle, edited by J. Barnes. Princeton: Princeton University Press, 1984.

Lawrence, T.E. Seven Pillars of Wisdom. London: Private Publication, 1926.

Mao Zedong. On Guerrilla Warfare (Yu Chi Chan). Translated by S.B. Griffith. Urbana: University of Illinois Press, 1937.

Articles

Murphy, Timothy J. "Misconceptions about Irregular Warfare." Parameters 54, no. 1 (2024): 15-28.

Multimedia

Army University Press. "Irregular Warfare: Defining the Indefinable." YouTube Video, 25:00. Fort Leavenworth, KS: U.S. Army Combined Arms Center, November 1, 2024. https://www.youtube.com/watch?v=1vfPOPVaHvM

Additional Credits

The categorization and analysis of definitional approaches presented in this article emerged through numerous discussions with Mr. Serge French of USSOCOM. His persistent questioning and rigorous examination of how irregular warfare is—and isn't—defined helped crystallize many of the logical fallacies and problematic approaches identified here. The release of the Army University Press Irregular Warfare video provided a timely example of these definitional challenges, but the theoretical framework for analyzing these approaches developed through intellectual discourse with Mr. French. His commitment to precise military thought and clear conceptual understanding significantly influenced the development of this analytical framework.

About the Author

CW5 Maurice "Duc" DuClos currently serves as a Guest Lecturer at the Naval Postgraduate School (NPS) in Monterey, California. His professional background includes various positions at the United States Special Operations Command (USSOCOM) Joint Special Operations University (JSOU), the U.S. Army John F. Kennedy Special Warfare Center and School (USAJFKSWCS), 1st Special Forces Group (Airborne) and 2/75th Ranger Battalion.

The views expressed are those of the author and do not reflect the official position of the United States Special Operations Command, Joint Special Operations University, or the Naval Postgraduate School.