This article is concerned with explaining why peace endures in countries that have experienced a civil armed conflict. We use a mixed methods approach by evaluating six case studies (Burundi, East Timor, El Salvador, Liberia, Nepal, Sierra Leone) and survival analysis that allows us to consider 205 peace episodes since 1990. We find that it is difficult to explain why peace endures using statistical analysis but there is some indication that conflict termination is important in post-conflict stabilisation: negotiated settlements are more likely to break down than military victories. We also consider the impact of UN peacekeeping operations on the duration of peace but find little evidence of their contribution. However, in situations where UN peacekeeping operations are deployed in support of negotiated settlements they do seem to contribute to peace stabilisation.

When state capacity dissolves, we ordinarily assume that violent conflict will break out, and then spiral towards a high degree of intensity. However, this is not always the case. Rather, on occasion, states suffer a sharp and severe loss of capacity, but little or no collective violence follows. And, on other occasions, violent conflict erupts, but that conflict does not escalate into civil war; rather, it plateaus, and then recedes. This article offers an analytic framework for explaining such variation in the presence, absence, and intensity of violent conflict following a dissolution of state capacity. I argue that the strength of state and societal organs prior to a loss of state capacity shapes the broad trajectory of violence after such a loss. In making that claim, I associate three state-society dynamics before state dissolution with three levels of violent conflict, post-dissolution. Drawing on multi-country fieldwork, I illustrate the proposed framework by presenting three diverse cases of dissolving state capacity and conflict: Georgia (1991–3); Albania (1991–2); and Yemen (2011–13).

Fears about the security of supplies have been central to debates about the development of an integrated EU energy policy over the past decade, leading to claims that energy has been ‘securitised’. Previous analyses have found, however, that although shared security concerns are frequently used as justification for further integration, they can also serve as a rationale for Member States to resist sharing sovereignty. Transcending this apparent paradox would require not just agreement about whether energy supplies are security concerns, but also agreement about what kind of security concern they are. In this article, we examine whether such an agreement could emerge through a comparative analysis of constructions of gas security in the UK and Poland. Utilising a framework that draws from both the philosophical and sociological wings of Securitisation Studies, we demonstrate that although gas has been elevated on the security agendas of both states, the specific logic of insecurity – securitisation or riskification – underpinning these constructions differs substantially, and is conditioned by distinct modes of governance in each Member State. This, we contend, limits the potential for further integration of EU energy policies in the context of the European Commission’s proposals for an ‘Energy Union’.

Assessing the risk of nuclear terrorism is a challenging task due to the diversity of actors involved, variety of pathways to success, range of defensive measures employed, and the lack of detailed historical record upon which to base analysis. Numerical models developed to date vary wildly in both approach and ultimate assessment: estimates of the likelihood a nuclear terrorist attack differ by up to nine orders of magnitude. This article critiques existing efforts from the standpoint of probability theory, and proposes an alternative perspective on the utility of risk assessment in this area. Nuclear terrorism is argued to be a ‘virtual risk’ for which it is not possible to meaningfully ascribe a quantitative measure, making numerical estimates of the likelihood of nuclear terrorism misleading. Instead, we argue that focus should be placed on utilising models to identify areas of disagreement as targets for further research, with greater emphasis on understanding terrorist decision-making and adaption in response to nuclear security measures.

This article examines the conflict between traditional Marxist attitudes toward war and the problem of the nuclear revolution. It shows how the advent of the nuclear revolution in the 1950s undermined traditional Marxist-Leninist concepts of war, and then goes on to argue that this development must be placed at the centre of contemporary Marxian IR if it is to have explanatory power in the twenty-first century. To make this case directly, it engages with Justin Rosenberg’s revival of Trotsky’s idea of uneven and combined development and its subsidiary law of ‘the whip of external necessity’, and argues that the whip can remain salient today only if one accepts the political utility of nuclear war. The impasse created by the nuclear revolution, it concludes, points Marxist IR in the direction of classic Marxist visions of supranationalism and human unity.

Overconfidence in the controllability of nuclear weapons creates danger. The passing of the last elite witness of the most dangerous nuclear crisis, that is, the ‘Cuban Missile Crisis’, and the current Trump administration only make this more salient. In this context, this article reviews the scholarly literature about the limits of predictability and controllability of nuclear crises and investigates three failures of learning from them. Given that France displays in particularly acute form some of the sources of overconfidence in the controllability of nuclear crises that can been found in other nuclear armed states, this article offers the first study of the French experience and evolving interpretation of the Cuban missile crisis in comparative perspective, based on untapped primary material. In security studies, this article makes three contributions. First, the publication and interpretation of primary sources is a contribution in itself given the frequent misconceptions about nuclear dynamics due to theory-driven extrapolations. Second, it challenges a widespread assumption of automaticity linking a fear-induced deterrent effect and the presence of nuclear weapons. Third, empirically, this article studies part of a regime of valuation of nuclear weapons. It finally outlines a research agenda to take luck seriously in security studies.