In 2014, the USA initiated the formation of a multilateral military operation against Daesh in Syria and Iraq. Eventually, more than 70 states joined the anti-Daesh coalition. However, contributions to the military effort have been characterized by great variance, especially among EU member states. While some states took leading roles in the airstrikes, others provided training for Iraqi and Kurdish forces, and still others did not get involved beyond voicing their support for the policy. Against this backdrop, this article makes a two-fold contribution to the literature on military coalitions and security policy. Empirically, the article provides a mapping of the then 28 EU member states’ military engagement in the fight against Daesh in Syria and Iraq. Analytically, fuzzy-set Qualitative Comparative Analysis (fsQCA) is applied to account for the observed pattern of military involvement, using an integrative framework that combines international and domestic factors. The results demonstrate that multiple paths led towards EU military involvement in the anti-Daesh coalition. At the same time, international-level incentives, such as external threat and/or alliance value feature prominently in all three identified paths. The analysis further underscores the value of a configurational perspective, because neither an external threat nor alliance value are sufficient on their own to bring about the outcome. Across the set-theoretic configurations, these conditions either combine with other ‘push’ factors or with the absence of constraints against military involvement. In line with the latter, the article highlights the policy relevance of institutional constraints, especially legislative veto rights, since most of those countries that were involved in the airstrikes of the anti-Daesh coalition did not have formal parliamentary involvement on matters of military deployment policy.

Only two European countries – France and the UK, both NATO members – have nuclear weapons, and leading politicians have called for the UK and EU to maintain close military and security links post-Brexit. In the context of the Trident renewal debate and the UK government's recently published integrated defence and security review, this article uses data from the new UK Security Survey to analyse attitudes towards the possession of nuclear weapons among the British public. It assesses three key theorical strands in the wider scholarly literature on public opinion and states’ use of military force: domestic political attitudes, foreign policy predispositions, and the ‘gender gap’. We find that all three theoretical perspectives contribute to the underpinnings of contemporary public opinion towards nuclear weapons. Support for the retention of Britain's nuclear deterrent is associated with being a Conservative Party supporter, favouring Brexit, endorsing superior military power worldwide as an important foreign policy goal, wanting to protect the transatlantic relationship, and with being male. The article makes a distinctive contribution to the growing subfield of research on public opinion and foreign policy, while the findings advance wider empirical understanding of contemporary citizen engagement in a key dimension of security policy.

Japanese security policy has undergone a significant degree of evolution since the early 1990s. As a result, the range of responses Japan can make in international crisis has significantly expanded. The gradual evolution and expansion of the Japanese security policy culminated in the legislation of security-related bills under the second Abe administration in September 2015. The security-related bills dramatically transformed Japanese security policy as it allowed Japan to exercise the right of collective defense when certain conditions are met. The gradual change of Japanese security policy has so far gathered much academic attention. There is a strong claim in the existing literature on Japanese security policy that changes in security policies became possible because of reforms in domestic institutions, which had expanded the Japanese prime minister's power. It is the contention of this article that the Japanese prime minister is still faced with severe constraints from the Diet, in particular from the House of Councilors even after a series of institutional reforms has empowered Japanese prime ministers to significantly alter Japanese security policy. It demonstrates that as the House of Councilors has significant power in the Japanese political system, some Japanese prime ministers had to have the implementation of some security policies delayed or was driven to revise some policies they had originally envisioned through several case studies.

Union external action after Constitutional set back – Status under international law – Perspective of democracy and leadership – Pillar structure – Substance and ambition of Union's foreign action.