‘Hybrid warfare’ as an academic fashion

ABSTRACT The ‘hybrid warfare’ concept had been coined years earlier, but became fashionable only when it was adopted and adapted by NATO in 2014, after which academic interest suddenly sky-rocketed. Academics often adopted NATO’s understanding of the concept, took for granted its fit for Russian actions, and imported its political assumptions into the academic debate. The fashionability of the term also led to bandwagoning and thus superficial engagement with both the concept and the phenomenon it was applied to. This article outlines this process and its implications for the field of Strategic Studies.


Introduction
'Hybrid warfare' does not seem to need much introduction, and yet it does. 1 Developed around 2007 by the U.S. Marine Corps, the concept made its 'breakthrough' on the international stage only when NATO used it in reference to Russia's annexation of Crimea and involvement in civil war in Eastern Ukraine in 2014. Since then, the concept has become a constant feature of academic and practitioners' publications and debates related to Russia and/or the future of war and warfare. Through this widespread use, the concept's meaning has become increasingly vague and ambiguous. Today, it seems one cannot use the term without first having to clarify its history and changes in meaning. 2 While the concept remains popular with academics and political and military practitioners, it has faced increasing criticism, and can be considered past its peak in popularity. 3 Some might link this to the initiation of Putin's war of aggression against Ukraine: having become increasingly focused on non-military elements of conflict, 'hybrid warfare' now seems less relevant to capture Russia's approach to war, despite the fact that Russia's actions in Ukraine from 2014 to 2021 had been treated as the prototype of 'hybrid warfare'. However, the concept's decline had already started earlier and can be explained largely based on its internal dynamics.
As this article argues, the 'hybrid warfare' concept can be considered a fashion -a powerful and wide-reaching, yet transitory phenomenon. While it may never completely vanish from academic debates, the concept has certainly lost much of its power and attraction. Yet, this does not mean that we should move on and forget about this episode. Rather, the intense embrace of an arguably flawed concept should encourage us to reflect on concept formation and use in Strategic Studies. Understanding why this concept has become so popular and how this popularity has affected research might allow us to draw broader conclusions on the value and role of concepts in the field. The case of 'hybrid warfare' is especially useful to understand when concepts become fashionable: even though the concept had been coined around 2007, academics had essentially no interest in it before 2014. Yet, after NATO used the concept to narrate Russia's actions in Ukraine, references to the term increased exponentially. Almost overnight, the concept became the way to refer to Russia's actions in Ukraine and its foreign policy more generally. 4 Thereafter, it also served as departure for speculations about scenarios of future Russian interventions elsewhere and the future of warfare more generally. 5 This article, therefore, specifically looks at this moment in 2014 when 'hybrid warfare' became fashionable and its effects. It first outlines what I mean by fashionable concepts and why I consider them worthy of investigation. The second section discusses the concept's origins and NATO's 2014 adaptation. The third section looks in detail at how this reconceptualization affected academic research, approximated through journal articles published from 2014 to 2021. It argues that the fashionability of 'hybrid warfare' led to the politicisation of academic research and discouraged in-depth engagement with both the concept and the phenomenon it was applied to. Importantly, this section shows how the concept itself became powerful. The fashion perspective thus allows us to understand the widespread use of a concept based on internal dynamics rather than (just) as a function of funding. The final section of the article reflects on implications of this argument for concept formation and use in Strategic Studies more generally.

Studying concepts as fashions
Concepts are mental constructs through which we 'make sense of a messy reality by reducing its complexity and naming and giving meaning to its features'. 6 A concept can be considered to consist of a label, its definition or characteristics (intension), and its associated material instantiations (extension). 7 Research in cognitive science has shown that human categorisation does not happen based on necessary and sufficient conditions, but is more complex than this three-element definition would suggest. 8 Yet, as tools to understand reality, academic concepts have to have a basic level of coherence; they need to have a (temporarily fixed) essence to be useful, even if their material manifestations will take different forms and their meaning might change over the long haul. Moreover, they must be operationalizable. Without such common ground, the theoretical and practical benefit of a concept will get lost. 9 As Colin Gray argued, '[s]trategic concepts are not dictated to us; rather, we choose them and decide how they can serve as building blocks for the edifice of theory we prefer'. 10 This quote conveys two important messages for students of strategy: first, we choose our concepts. Some concepts might fit a situation better than others; but the perception of such a fit depends on the aspects of the situation that are relevant to the conceptualiser. A concept never captures the entire situation, but by necessity highlights some aspects while backgrounding others. 11 Developing or choosing a concept is about 'deciding what is important about an entity'. 12 Second, we choose concepts for a certain aim. Since concepts can never fully reflect reality, they cannot be true or false, but only more or less useful for said aim. Within academia, this aim broadly relates to understanding and explanation, in some traditions also prediction. Strategic Studies specifically focuses on understanding and explaining the 'threat, use, and control of military force', 13 in order to enrich strategic theory and practice. 14 The term 'fashion' refers to a dynamic: the sudden, widespread, intense, but also transitory embrace of an idea, a behaviour, or an item that grants attractive and coercive power to it. Though short-lived, its duration can vary from weeks to years. The concept cycle differs from the fashion cycle, and the concept and the fashion thereof are not necessarily the same. Fashion is about the dynamics of how the concept is engaged with. If a concept becomes fashionable, it is engaged with superficially and partially, with a high sense of urgency and emotion. 15 Yet, the concept may exist before and after its period of fashionability.
Importantly, fashion is about power. The fashion cycle usually starts off when the concept is granted authority, for example, by a person or institution with authority and power; soon the fashionable concept develops power by itself and cannot be controlled by the original conceptualiser (which, in the case of 'hybrid warfare', is Frank Hoffman) or the initial granter of authority (NATO). This power is both attractive and coercive. It attracts the interest of scholars, for example, by creating new avenues for research and demand for publications. But it might also coerce people into using the term, for example, to signal their awareness of the ongoing debate. The power of fashionable concepts thus leads to bandwagoning, a diffusion process in which scholars adopt a term not because they view it as useful for analytical purposes, but simply because many other scholars or relevant institutions have adopted it. 16 To perform this signalling role, no deeper engagement with the concept is necessary. Bandwagoning thus encourages superficial engagement. Moreover, it necessarily leads to vagueness and ambiguity. 17 As more and more people use a concept, its definitions and understandings will vary. The attractive power of the concept might encourage scholars to hook their topic of interest to it, even if there is no direct connection. Bandwagoning, however, does not necessarily include only favourable uses of the term: critical discussions of the concept, too, will benefit from the interest in a fashionable concept. Yet, irrespective of the content, bandwagoning is a self-reinforcing process through which a fashion becomes ever more powerful while alternative views are marginalised. 18 Due to these dynamics, fashionable concepts may have negative effects on research.

How 'hybrid warfare' became powerful
Although the first discussion of 'hybrid warfare' goes back to at least 2002, 19 it was Frank Hoffman's publications that introduced the concept to a wider audience. In a 2007 paper, which many consider the foundational text for the concept, Hoffman argued that 'Hybrid Wars incorporate a range of different modes of warfare, including conventional capabilities, irregular tactics and formations, terrorist acts including indiscriminate violence and coercion, and criminal disorder'. 20 For Hoffman, the essence of 'hybrid warfare' was the blurring, or convergence, of different modes of warfare and different actors. In 'hybrid wars', regular and irregular forces are 'operationally integrated and tactically fused'; they are part of 'the same force in the same battlespace'. 21 Hoffman, who wrote this paper while a research fellow at the Marine Corps' Center for Emerging Threats and Opportunities (CETO), aimed at preparing the Marine Corps for the future conflict environment. His conceptualisation of 'hybrid warfare' has to be understood not only against the backdrop of the 2006 war between Hezbollah and Israel (which he discussed as prototype case), but also as a response to the rigid conceptual distinction between conventional and irregular war(fare) in US strategic thought and practice. Warning against the assumption of a given link between the nature of actors and their preference for means, Hoffman argued that actors would see different means as a 'menu' from which to choose flexibly according to their aims and culture. 22 Judged against this background, his intervention seems useful for the purpose of spurring more creative and flexible thinking when assessing the future security environment from the perspective of a US military institution.
Hoffman made a concerted effort to diffuse his concept through publications and briefings. 23  At the 2014 NATO Summit in Wales, the 'hybrid threats' concept was used to frame events in Ukraine. The Summit Declaration defined 'hybrid warfare threats' as situations 'where a wide range of overt and covert military, paramilitary, and civilian measures are employed in a highly integrated design '. 35 While this definition resembled Hoffman's ideas, succeeding NATO publications offered different views that were shaped by Russian actions in Ukraine. A NATO Defense College publication on NATO's Response to Hybrid Threats argued that 'hybrid wars' 'use a wide array of means to convey a political or ideological message from the battlefield to the world without regard for international laws or norms, and without even necessarily proposing an alternative model'. 36 Sorin Dumitru Ducaru, NATO Assistant Secretary General for Emerging Security Challenges, argued that 'the HW approach aims to . . . generate surprise, . . . seize the initiative, . . . generate deception and ambiguity, . . . avoid attribution of action; [and] maximize deniability of responsibility for aggressive actions'. 37 He continued to maintain that 'hybrid warfare' is 'directed at an adversary's vulnerabilities, focused on complicating decision making'. 38 A NATO Defence College research paper defined 'hybrid warfare' as 'an effective and sometimes surprising mix of military and nonmilitary, conventional and irregular components, [that] can include all kinds of instruments such as cyber and information operations'. 39 It further outlined that '[n]one of the single components is new; it is the combination and orchestration of different actions that achieves a surprise effect and creates ambiguity, making an adequate reaction extremely difficult, especially for multinational organizations that operate on the principle of consensus'. 40 The aspects of surprise and ambiguity were not part of either Hoffman's or NATO's pre-2014 understanding of the concept. Similarly, some means that were now considered 'typical' for 'hybrid warfare' had not featured in earlier conceptualizations. Indeed, in July 2014, Hoffman pointed out that his original concept '[except for criminal acts] completely fails to capture other nonviolent actions. Thus, it does not address instruments including economic and financial acts, subversive political acts like creating or covertly exploiting trade unions and NGOs as fronts, or information operations using false websites and planted newspaper articles'. 41  attention to the necessity of a capability review. 42 Based on interviews with NATO officials, they concluded 'that the term hybrid warfare is a label or a tool that is used for internal purposes at NATO such as "to wake the system up", "to put a debate on the table", "to increase awareness", "to review capabilities" and "to secure the defence budget" rather than a concept which postulates a framework of principles on how to engage in modern warfare'. 43 Other scholars have identified additional functions of the concept for practitioners, such as the justification for the West's limited reaction or as source of identity and relevance. 44 The specific definitions brought forward by NATO publications support these conclusions. Rather than discussing the essence of this hybrid approach to warfare, they include the specificities of the Russian case, such as the effect of surprise, the apparent ambiguity of Russian means and aims, or Russia's disregard for international law. In many ways, these definitions reflect NATO's perceptions and emotions rather than Russian actions. With this reconceptualization, 'hybrid warfare' turned from an operational concept into a political narrative that attributed aims to Russia's actions based on the effects of those actions as perceived by NATO.
Originally focused on operational aspects, the concept now captured the entire spectrum of military and non-military means, with an increasing focus on the latter.

Impact on the academic debate
Scholars in Strategic Studies only really got interested in 'hybrid warfare' after 2014, when references to the concept increased exponentially. NATO did not simply use the term to frame a key event in European security, but also elevated 'hybrid warfare' to the top of its agenda. Similarly, senior EU and national politicians frequently referred to Russia's 'hybrid warfare' threat. Together, NATO and the EU founded the European Centre of Excellence for Countering Hybrid Threats. 45 These aspects, of course, made the topic very attractive to scholars who wanted to offer policy-relevant contributions, a sought-after output in today's academic institutions. Figure 1  zooms in on articles that engage in some depth with 'hybrid warfare' (i.e., invoke it in their title, abstract, or keywords) and use the concept to make sense of Russia's behaviour and/or of current and future modes of warfare. By 2014, the concept had already been inherently linked to Russia and reconceptualised based on this case; both its extension and intension had changed so much that all it had in common with Hoffman's version was the label. While academics still acknowledged the concept's origins, those who used the concept approvingly tended to replicate NATO's narrative; some even used NATO's definition of the term to guide their academic analysis. 48 This section of the academic literature took for granted that Russia successfully used 'hybrid warfare' in Ukraine. 49 Here too, NATO's perception of the effects of Russian actions in Ukraine were incorporated into the concept. Lanoszka claimed that . . . hybrid warfare exploits the vulnerability of targets at yet lower levels of violence, whereby the belligerent can plausibly deny that it is even engaging in aggression. The belligerent could thus deter its target from undertaking escalatory measures. It also denies adversaries a clear, compelling rationale for military intervention by obfuscating the nature of local crises fomented from without. 50 For Stavridis, The fundamental goal of hybrid warfare is to find the space short of obvious military action that nevertheless has direct and recognisable tactical, operational and strategic impact, and to compress hostile activities into a zone characterised by sufficient ambiguity to give an aggressor a better chance of accomplishing an objective without full-blown, overt offensive action. 51

Mälksoo argued that
Hybrid warfare exposes collective actors to the fundamental existential questions about the continuity of their external environment as they know it and their own finitude, with the related anxiety about the difficulties of concretising unknown and indeterminate threats . . .. 52 What is especially interesting is that Lanoszka and Mälksoo treat 'hybrid warfare' as the actor. It is supposedly 'hybrid warfare' itself that offers certain benefits, independent of the situation. As Renz has argued, this ignores the 'extremely favourable circumstances' that made Russia's success in Crimea possible and 'are unlikely to work in a different scenario'. 53 Indeed, there is a pattern in articles that use the concept approvingly to generalise from the Russian case to a broader conception of 'hybrid warfare'. Rather than acknowledging that their understanding of 'hybrid warfare' is derived solely from the Russian case, authors tend to portray 'hybrid warfare' as a general approach to war that had already existed and was ably applied by Russia. Thus, authors could claim, for example, that 'hybrid warfare' 'can bestow the advantage of surprise', 54 while it was, of course, Russia who was able to create this moment of surprise, largely benefitting from Western ignorance. By claiming that the 'hybrid warfare' approach is powerful by itself, commentators not only inflated its threat potential, but also depoliticised and destrategised the approach by decoupling it from Russia's political and military aims.
Throughout most of the literature, the fit of the 'hybrid warfare' concept as well as Russia's success were taken for granted, which meant that 50 Alexander Lanoszka, 'Russian Hybrid Warfare and Extended Deterrence in Eastern Europe', International Affairs 92/1 (2016), 175-195. 51 Stavridis, 'VI. The United States'. 52 Mälksoo, 'Countering Hybrid Warfare', 378. 53 Renz, 'Russia and "Hybrid Warfare"', 284. 54 Stavridis, 'VI. The United States', 95. developments in Ukraine were not explored in depth. Russia's annexation of Crimea and engagement in Eastern Ukraine were usually invoked together as if they were the same event. 'Hybrid warfare' supposedly captured both operations equally. Not only were different contexts and conflict dynamics ignored; the fact that Crimea was taken essentially unopposed whereas the Donbas was experiencing war was not acknowledged. What is remarkable is also how little engagement there is with the essence of 'hybrid warfare' both as a strategy and a concept. If 'hybrid warfare' did indeed constitute or refer to a new kind of warfare, one might expect comprehensive engagement with events for the purpose of understanding how the combination of different means led to success. But the articles analysed here never established how exactly the hybridity of 'hybrid warfare' mattered. Instead, the concept and practice were described through an enumeration of different means, creating a list to which ever more means were added as scholars bandwagoned on the concept. This vagueness is both a requirement and an effect of fashionability: it made it easy for scholars to link their research interests to the topic of the day, which in turn made 'hybrid warfare' yet more visible and powerful.
Relatedly, there was a lack of engagement with Russia's aims, which is arguably necessary to make any conclusions about the extent of Russia's success. Rather than trying to understand these aims, authors extrapolated supposed aims from the effects of means. One consequence of that was, as noted above, that 'hybrid warfare' was seen as the actor, as a powerful tool that offers immense opportunities. Actors' intentions and agency were largely ignored, and the conflict dynamics were depoliticised. Having extrapolated aims from effects, the literature then moved on to draw future scenarios of Russian 'hybrid warfare' interventions, which typically took place in the Baltics. 55 Not only did this inflate the threat coming from the supposed practice of 'hybrid warfare', making the idea more powerful; it also imposed a Western interpretation on Russia's actions that ignored or misunderstood Russian strategic thought. 56 It is telling that those who engaged with events in more depth do not find the concept particularly useful. 57 As the concept diffused, its vagueness and ambiguity increased. Already in Hoffman's 2007 publication, the labels 'hybrid warfare', 'hybrid war', and 'hybrid threat' were used almost interchangeably, and this trend continued as the concept was used more widely. The synonymous use of 'war' and 'warfare' is not distinct to commentators on 'hybrid warfare', but can be detected with many popular concepts such as 'information war/fare' or 'cyber war/fare'. 58 War and warfare are not the same, however; whereas 'warfare' refers to the actual fighting, 'war' refers to the overall phenomenon that goes beyond fighting but might (temporarily) also exist without any ongoing fighting. The fact that commentators in the field pay little attention to the distinction of these basic concepts is problematic and an indication of the lack of conceptual awareness and robustness. In addition to this, the focus of the concept quickly moved from the combination of military and non-military means to only the latter. It was this aspect of the Russian approach to Ukraine (and its supposed success) that particularly captured Western imagination. This is obvious from NATO publications: the Strategic Communications Hybrid Threats Toolkit, for example, identifies '13 key types of hybrid threat', only two of which include the use of force. 59 In the academic articles analysed for this research, the increasing focus on nonmilitary means led to serious confusion about what war is. Even though fighting was taking place in Eastern Ukraine, many considered Russian 'hybrid warfare' directed towards the West. Indeed, Russia did target different Western countries with disinformation campaigns; however, the use of force (or threat thereof) was restricted to Ukraine. Considering Russia's actions as warfare against the West is thus misleading, at the very least. 60 The concept's focus on non-military means was further foregrounded through its connection to the concept of the 'grey zone', which refers to a supposedly ambiguous space between war and peace, where competition takes place 'primarily below the threshold of armed conflict'. 61 Around 2017, the 'grey zone' and 'hybrid warfare' had become almost synonymous in both academic and practitioners' publications. 62 The 'hybrid warfare' concept, therefore, mostly implicitly rather than well-argued, challenged the field's central understanding of war. 63 In general, 'hybrid warfare's' delineation to existing concepts was often unclear, as the following examples illustrate: Hybrid-also known as nonlinear or sub-conventional-warfare . . . 64 Sometimes also called 'new-generation warfare,' 'non-linear war,' 'ambiguous war,' or 'gray-zone conflict,' hybrid war is perhaps best illustrated by the Russian government's efforts to undermine the government of Ukraine . . . 65 Emerging strategies that seek to act in this manner, such as those employed by Russia in Ukraine, use all the levers of power available to decision-makers and have become known as 'grey zone' or 'hybrid' strategies. 66 Two interventions might be useful here. First, if these concepts were referring to the same phenomenon as these quotes suggest, why add another one? However, second, as experts on Russian strategic thought have repeatedly argued, these concepts do not mean the same thing. 67 As outlined above, 'fashion' refers to a dynamic: the sudden and intense embrace that creates attractive and coercive power. In academia, the 'hybrid warfare' concept became fashionable around 2014, i.e., after NATO had reconceptualised it to reflect its impression of the Russian intervention in Ukraine. Importantly, it was also because NATO used the concept for this purpose that academics became interested in it. It was thus NATO's post-2014 version of the concept that diffused in the academic literature; and, indeed, the similarities between NATO and academic discourses are astonishing. NATO's use of the concept as a frame to understand Russia's actions in Ukraine led to its politicisation, i.e., its instrumentalization to push political and institutional interests. It created a specific interpretation that served other functions than analytical clarity: a tool to refer to the military 'revival' of Russia, a communicative warning signal within NATO and the EU. Even in academia, it seems the term was often used for this communicative function rather than as analytical tool. The fact that Russia's successful use of 'hybrid warfare' was taken for granted gave the concept immense power and relevance that attracted further interest and encouraged commentators to speculate about the future use of 'hybrid warfare'. This power increased the pace and urgency of the debate. It encouraged bandwagoning on the dominant narrative and discouraged in-depth engagements with events in Ukraine or the concept and its relation to existing concepts and strategic theory. As the number of articles exercising the concept increased, so did its vagueness and ambiguity.
Paradoxically, critical engagement with the concept, too, benefitted from and contributed to the concept's popularity. Yet, critical contributions were of a somewhat different character. First and foremost, it is notable that criticism mainly came from authoritative and established figures in the field. 68 Inadvertently, their joining the debate might have added more authority to it. But more interestingly, this might suggest that to go against the authority of a fashionable concept, the authors themselves need a certain degree of authority. Secondly, these publications stand apart in their detailed engagement with the concept. While such engagement is obviously necessary for an effective critique, the same should arguably also hold true for an effective application of the concept. It is impossible to measure the effect of these criticisms, but it is clear that 'hybrid warfare' was able to withstand them for some time. Importantly, at the height of the concept's fashionability, its promoters barely felt the need to engage with such criticism. This is typical of a fashionable concept, which, due to its power and taken-for-grantedness, does not require justification. Indeed, the need to justify the use of a concept can be correlated with its power and fashionability -it is visible only when a concept is not yet powerful or when this power is slowly starting to falter. 69 Starting around 2020, this need has increasingly become visible in the case of 'hybrid warfare': authors using the concept approvingly had to acknowledge changes in its meaning as well as criticism of it before proceeding to applying the concept. Another sign of decreasing power is the emergence of secondary analyses which do not use the concept as a tool to be applied to a research object, but rather consider the concept itself as their research object. 70 The existence of such analyses suggests that the meaning and usefulness of the concept are not taken for granted anymore. At the same time, the term was also increasingly assimilated with the 'grey zone' concept, which, as suggested above, meant a further step away from its original meaning to an increased focus on the non-military aspects before war. It also linked 'hybrid warfare' to the case of China whose actions in the South China Sea are seen as the prototype of 'grey zone' activities. This can be read as an attempt to reaffirm the power of 'hybrid warfare' by linking it to another fashionable concept that still was in its prime and to an additional case that currently attracts much interest in policy and academic circles.
While 'hybrid warfare' is still frequently invoked, the ways in which it is dealt with in academic articles clearly shows that it has lost much of its power. In fact, the reasons for its decline are inherently linked to the characteristics that made it fashionable in the first place: its politicisation, its vagueness, its focus on one case, and its intense embrace that exaggerated its explanatory power.

Implications for the field of strategic studies
This discussion has foregrounded two aspects of 'hybrid warfare' as an academic fashion: first, its institutionalisation by NATO which attracted and shaped academic interest in the concept; second, the concept's vagueness and ambiguity and the superficial engagement with the concept and events that resulted from bandwagoning. This section reflects on what these two aspects mean for the field and whether fashionable concepts can still be useful. NATO's adaptation of the 'hybrid warfare' label to narrate its own frustration with the effect of Russia's actions led to the politicisation of the concept. When scholars adopted the concept, they also took on board its underlying assumptions about Russia's intentions and success and the West's vulnerability to Russia's 'hybrid warfare'; the academic debate, thus, became entangled in this politicisation. 'Hybrid warfare' is not special in this regardother fashionable concepts in the field, too, originated with the US defence establishment and/or became fashionable in academia only after they became popular within said establishment. However, I am not calling for more 'neutral' concepts, as these do not exist. Rather, the issue is that academics are using a loaded concept while believing it is neutral. Even critics of the concept have never addressed the question whether a concept coined originally by the US Marine Corps and then popularized by NATO is an appropriate and useful tool to guide academic analysis.
Such conceptual cross-pollination is facilitated by the close connection between scholars and practitioners and the huge influence of current events on the field's research agenda. 71 Barry Buzan and Lene Hansen have argued that the field displays a 'dual ambition' to create knowledge that advances our scientific understanding as well as knowledge that can 'speak to major political decisions'. 72 The debate on 'hybrid warfare' offered an opportunity to produce seemingly policy-relevant contributions. The close connection is not restricted to ideas, but also includes personal interconnections and overlaps. 73 As a consequence, academics and practitioners almost equally contribute to the academic debate. Of the articles analysed for this research, just over half of the authors were affiliated with a civilian university, as Figure 2 shows. I do not want to suggest that this is necessarily problematic; at the very least, this offers another explanation for why the 'hybrid warfare' concept easily entered the academic debate.
Moreover, this links back to my earlier discussion of the aims of concepts, which argued that different aims guide concept formation and use in different sectors. Academia, very generally speaking, is geared towards better understanding -in the case of Strategic Studies mainly understanding aspects relating to the use of force for political purposes. In military organisations, on the other hand, concepts serve to illustrate how future joint and Army forces may operate, describe the capabilities required to carry out the range of military operations against adversaries in the expected operational environment (OE), and explain how a commander, using military art and science, might employ these capabilities to achieve desired effects and objectives. 74 Importantly, for military services, 'the purpose of a concept is to adapt the force for the future'. 75 As Jan Angstrom has argued, the 'hybrid warfare' concept sits (uncomfortably) between analysis and doctrine: it 'tries to combine the virtues of analytical concepts insofar as trying to tell us something about the development of war, but through stressing change and adaptation, the concept also includes the elasticity of doctrinal concepts'. 76 Doctrinal concepts may be more 'amorphous' as they often serve as tools to 'debate defense posture and scare-mongering'. 77 For this reason, they might be 'only distantly related to actual changes in warfare'. 78 Moreover, Jan Honig reminded us that doctrines -military or otherwise -are essentially belief systems; they 'do not argue a case'. 79 A concept that is suitable for theory-building or understanding war, on the other hand, needs to be precise and operationalizable. The necessity of introducing a new term as well as its relation to existing ones should be clearly outlined and justified. 80 Based on my discussion above, 'hybrid warfare' does not seem to meet any of these criteria.
In addition to aims, practitioners and academics differ in terms of tempo. Lawrence Freedman has illustrated this aspect: When a new policy problem emerges -arms control in the 1980s, ethnic conflict in the 1990s, terrorism in the 2000s, revived great power conflict in the 2010sthere will be a surge of activity as grants become available, conferences are held and new ideas for PhD dissertations suggest themselves. But by the time the call has been made and answered, funds have been allocated and researchers appointed, the research actually completed and the findings disseminated years will often have past [!], and the policy community may well have moved on to the next problem. 81 If the field's research agenda is too focused on the policy debate, the latter's pace and urgency are imported into academia. Frequent changes in topic may drag the field into different directions. One effect of the pronounced policy focus has been the continuous introduction of ad-hoc concepts into the existing conceptual system of the field. 82 As the discussion on the increasing vagueness and ambiguity of 'hybrid warfare' has shown, the potentially harmful effects on our ability to make sense of events and even our own concepts should not be underestimated. The inconsistent use of the concept in regard to its label, intension, and extension has not only diminished its usefulness for analytical purposes; it has also unsettled related concepts and challenged the field's basic understanding of war.
The answer to the problem of fashionable concepts is, however, not for academics to detach themselves completely from practitioners; the key concern of my discussion is not whether the field engages with ongoing events and political debates, but how. The 'hybrid warfare' debate has brought to light the need to strengthen and highlight the field's conceptual foundations, to improve conceptual resilience, 83 and to encourage a more careful and explicit engagement with concepts. This might be especially relevant when concepts are imported from outside of the field, be that from other fields and disciplines or military discourses. Additionally, the centrality of strategic theory should be highlighted. As Caliskan has argued, introducing a new concept was not necessary in order to capture Russia's actions -existing strategic theory is a better guide to understand contemporary warfare. 84 This leaves the question whether fashionable concepts can still be useful. Indeed, in a way, 'hybrid warfare' did capture the Zeitgeist of the time in the sense that great power competition was in fact changing -both Russia and China were acting more aggressively; especially Russia used comparatively 'new' means in this competition. It exploited the strength and breadth that social media had reached by then, which allowed disinformation campaigns to spread much more quickly (which does not automatically mean more successfully); both the use of social media to spread misinformation and the attacks on computer networks as part of inter-state competition might have been hitherto undertheorized. The 'hybrid warfare' concept did help to foreground these aspects. This initial benefit, however, was soon lost, for reasons that have been discussed in detail in this article. 85 In sum, the 'hybrid warfare' concept does potentially point to some avenues for future research, even though it should not be used to guide those research endeavours.

Conclusion
Often, when a new term is introduced in Strategic Studies, the first strand of criticism, and thus the first phase of the debate, focuses on whether the term refers to something new. This, however, misses the point; novelty is not what determines the necessity of a new concept. A practice might be centuries old, but -for different reasons -not have been considered relevant enough to merit its own concept. Concepts do not capture what is new but what is important. The 'hybrid warfare' concept should, therefore, not be criticised for capturing an old technique. Rather, the question should be whether it is useful for our purposes. As this article has aimed to show, the answer to this question depends on where one sits. For practitioners, it seems to have been useful to some extent to raise awareness and encourage debate about defence capabilities. But for this purpose, the concept captured feelings and perceptions rather than events. Within academia, on the other hand, the concept has contributed little to our understanding of the supposed use of 'hybrid warfare' in Ukraine or its relevance for future wars. Instead, the introduction of the concept has led to the politicisation of the debate and superficial engagement with the concept and the phenomenon in question. It offered a ready-made interpretation of the conflict in Ukraine as 84 Caliskan, 'Hybrid Warfare through the Lens of Strategic Theory'. 85 See also Renz, 'Russia and "Hybrid Warfare"'. well as Russia's intentions in and beyond Ukraine, and narrowed what researchers are looking at and how, and, hence, which conclusions they draw.
A key lesson from the 'hybrid warfare' fashion should, therefore, be that the field needs to strengthen its conceptual base and reflect more critically on how concepts are formed and used. Even though the field is well aware of the power of language to influence others -as epitomised in the flourishing research area of Strategic Communications -the impact of its own concepts is poorly understood. This article has aimed to outline how the fashionability of 'hybrid warfare' has affected research in this area. Fashions are a social phenomenon and can, thus, not be abolished or suppressed. But the discussion in this article hopefully has offered reasons why it is still worth resisting them.