This article challenges the perception of Open-Source Intelligence (OSINT) as a revolutionary shift driven by the explosion of publicly accessible data. Instead, we argue that the rise of OSINT reflects an evolution of traditional intelligence practices: the collection, processing, analysis and dissemination of vast amounts of information. While the exponential growth of open–source data is reshaping the intelligence landscape, it is neither revolutionizing nor democratizing intelligence. Rather, it is prompting both state and non–state actors to explore how best to integrate OSINT practices and enhance digital literacy within their communities. Core OSINT challenges – information overload, reliability, and legal and ethical concerns – remain consistent with broader intelligence issues. Addressing these challenges provides a foundation for consolidating OSINT as a community of practice, and linking it to debates on the disputed role of security expertise in the public debate.

What would it mean to decolonise the concept of war? ‘Decolonising’ means critiquing the ways in which Eurocentric ideas and historiographies have informed the basic categories of social and political thought. Dominant understandings of the concept of war derive from histories and sociologies of nation-state formation in the West. Accordingly, I critique this Eurocentric concept of war from the perspective of Small War in the colonies, that is, from the perspective of different histories and geographies of war and society than were assumed to exist in the West. I do so in order to outline a postcolonial concept of war and to identify some of the principles of inquiry that would inform a postcolonial war studies. These include conceiving force as an ordinary dimension of politics; situating force and war in transnational context, amid international hierarchies; and attending to the co-constitutive character of war and society relations in world politics.

Sabotage is ubiquitous but little understood in international relations. Sabotage, especially in terms of attacks on infrastructure and property, has increased in recent years and has taken a more central role in national security discourse across Europe. Unfortunately, scholarship is underdeveloped and fragmented across disciplinary silos, leading to conceptual confusion about the nature and scope of sabotage as a form of statecraft. This article seeks to provide conceptual clarity, and in doing so, lay the foundations to better understand and respond to such activity. It does so first by synthesizing ideas from disjointed literatures on conflict, intelligence, terrorism, public administration, and cybersecurity, before distilling key characteristics of sabotage and offering a novel definition. The article finds that sabotage is the weaponization of friction to degrade the performance of systems from within. Sabotage has a strategic logic distinct from related concepts of covert action and subversion: corrosively turning friction into advantage. This logic limits its impact as stand-alone tool but makes it particularly well-placed to enhance and enable other policy instruments. By placing sabotage on the research agenda and theoretically advancing scholarship on ‘secret statecraft’ more widely, this article has significant implications for understanding and responding to contemporary security challenges.

This article presents the study of ambiguity as the essence of hybrid warfare to reconcile it with the international political context. It addresses the gaps in the literature in an effort to elucidate the essence of hybrid warfare not as a separate concept, but rather as the symptom of a changing political environment. The analysis of the literature is reinforced by two case studies: the war in eastern Ukraine of 2014 and the South China Sea dispute. Both these case studies express ambiguity in the combination of kinetic and non-kinetic means used to achieve political objectives. The article rests on three pillars that constitute the architecture of the central argument. The first pillar will address the gap in the current literature on hybrid warfare and how the current debate is too concerned with conflict dynamics rather than its political nature. The second pillar will delineate the essence, characteristics, and value of ambiguity in hybrid warfare. The third pillar will address the practice of hybrid warfare as the conduct of war by great powers.

To what extent can drones be the primary determinants of victory in warfare? This question is at the heart of the drone revolution debate in security studies. Proponents of a drone revolution argue that drones provide ‘game-changing characteristics’, act as ‘magic bullets’ against adversaries, and even provide the key defence to decide the ‘fate of nations’. Sceptics disagree, arguing that no matter the nuances or contexts of war, drones can never be considered the primary determinant of victory. In this article, we argue that the two sides of the debate rest upon a false dichotomy – that technologies must either be revolutionary or evolutionary. We reappraise country-specific case studies used by both sides of the debate: the Ethiopia–Tigray War, the Houthi–Saudi War, and the Russia–Ukraine War. Our analysis reveals a welcome synthesis; the impact of drone employment depends on the types of war waged, the drone capabilities deployed, and the political objectives sought in each conflict. In this sense, drones can have an impact on war that is sometimes ordinary and sometimes revolutionary. It is only by clarifying the analytical scope of the debate that the impact of drones on the practice of war can be fully understood.

This article provides novel insights into Russia’s strategic use of migrants, using the Federal Security Service (FSB)-enabled migration flows towards Norway and Finland in 2015/16 as a case study. Through the use of semi-structured interviews and an empirical study, we identify several potential Russian goals tied to its use of migration, including restoring bilateral relations to the levels before Russia’s 2014 invasion of Ukraine, influencing the European Union’s (EU’s) decisions on sanctions and cooperation, warning Finland against seeking NATO membership, testing the effectiveness of a new tool, collecting intelligence, and weakening Western influence per Russia’s broader information confrontation towards the West. These objectives served the broader regional and grand strategic goals of maximising Russia’s influence and minimising the EU’s and NATO’s sway in the region. Our findings challenge earlier interpretations that downplayed Russia’s role, arguing instead that the operation established coercive potential rather than immediate concessions. We contribute to the literature on the strategic use of migration and authoritarian states’ innovative use of unconventional methods.

This article investigates the defence policies of the Nordic and Baltic countries from the perspective of shared security culture. To that end, the article analyses conceptualisations of total defence and resilience in a comparative perspective and inquires into existing and prospective regional cooperation in this area, in order to determine to what degree there exists a common security culture based on shared norms and identities and manifested in practices of security cooperation. The study, which draws on 19 interviews with civil servants from the eight states of the region, shows that while there is fertile ground for a shared security culture to emerge, thus far, due to variations in conceptualisations, threat perceptions, and interaction preferences, only three Nordic states show clear signs of a shared security culture. The study contributes to existing research by situating the concept of resilience in (total) defence discourses; by expanding the theoretical work on security culture to an international context; and by offering a unique empirical account of the process of (re)building total defence policies in a region crucial to European security.

The concept of hedging has been recently introduced and has been gaining traction in International Relations (IR) literature. So far, the notion has been mainly employed to make sense of the strategic behaviour of some south-east Asian secondary states amid growing Sino-American great power competition. Hedging can be understood as a strategy through which a minor state avoids clearly aligning vis-à-vis two powerful vying actors, maintaining instead an in-between and balanced position. As such, hedging can be interpreted as a peculiar form of neutrality. Yet such a paralleling has not been spelled out clearly from a theoretical standpoint in the existing literature. Moreover, no attempt has been made to precisely position hedging among the different categories of neutrality. This is a major gap, as it deprives the hedging concept of much of its theoretical and analytical usefulness in informing scholarly analyses. By precisely locating hedging within the neutrality family and by identifying its main analytical features, this paper aims to clarify theoretically the ‘nature’ of the phenomenon. At the same time, such operation aims to move the hedging literature beyond its current overwhelming focus on contemporary south-east Asia, opening up interesting empirical perspectives for the study of hedging across time.

A recent wave of survey experiments has advanced scholarly understanding of public attitudes towards the use of nuclear weapons. In this article, we address the central question: can public opinion influence decision-makers’ views on nuclear weapon use? We bridge this critical gap in the literature with a survey experiment conducted on samples of UK parliamentarians and US and UK government employees in official policy roles. We varied public support for nuclear strikes in realistic scenarios to examine participants’ responsiveness to public preferences when considering nuclear first use, nuclear retaliation, and third-party nuclear threats. We show that high public support notably increases willingness to endorse nuclear first use against non-nuclear adversaries. Furthermore, public backing shapes beliefs about national leaders’ willingness to order nuclear strikes. However, the effect of public opinion is weaker in nuclear retaliation contexts, suggesting that different considerations become prominent when the ‘nuclear taboo’ has been breached. Importantly, sympathetic public opinion strongly influences perceptions of the credibility of third-party nuclear threats, carrying implications for the practice of nuclear deterrence. Our findings highlight the role of public opinion as both an enabling and constraining force on nuclear use and provide new theoretical and empirical insights into elite decision-making in nuclear politics.

This article serves as the introduction to a Special Issue of the European Journal of International Security titled ‘What the War on Terror Leaves Behind’. In it, we seek to contextualise and summarise the diverse contributions of this collection, which is animated by four overarching questions: (i) More than 20 years after the attacks of 11 September 2001, is the War on Terror now, finally, over? (ii) What, if any, legacies remain from the post-9/11 way of thinking and doing counterterrorism? (iii) What is the significance of the War on Terror’s legacies or absence thereof? and, (iv) How do the War on Terror’s impacts and effects sit within other historical contexts and (dis)continuities? The article begins with a brief overview of some of the conceptual and political ambiguities of the War on Terror itself, before situating the issue in relation to issues of continuity and change anticipated by the four questions above. A second section then explores the urgency of these questions for academic debate, and in the ‘real world’ of international security as experienced by states, communities, and other subjects. A third section then summarises the argument and contributions of the articles in the issue –highlighting the lack of agreement on key issues within these debates.