In the past few years decision‐making processes and the normative underpinnings of EU external relations have become subject to intense debate in the European institutions, member states and the wider public. Previous research suggests that there is variation in the extent to which individual domains of EU external relations are politicized and contested. This special issue aims to theorize further and investigate empirically this, using the example of European development policy and its relations with other external policies. We introduce two new mechanisms that drive politicization dynamics. We argue that politicization can be diffused horizontally from one policy field to another, which we call horizontal politicization. We also investigate how the politicization of EU external policies in third countries occurs and influences politicization dynamics in the EU, which we call outside‐in politicization. The introduction to the special issue presents our theoretical approach and summarizes the key findings from the special issue.

Previous research suggests that the rise of populist radical right parties (PRRPs) is contributing to the politicization of European domestic and external policies. However, whether this is also the case for European development policy is unclear. Building on a new dataset that analyses government positions and coalition agreements across European countries since the 1990s, we investigate whether, and if so how, the strength of PRRPs affects European governments' framing of the relationship between migration and development policy. Research on PRRPs suggests that they influence other parties' positions directly when they are in government, or indirectly by framing topics such as migration differently from other parties, thereby pushing government and opposition parties to modify their own positions. We find (moderate) support for PRRPs' indirect influence on the framing and salience of the migration–development policy nexus, via their vote and seat share. The effect of PRRPs in government on the formulation of development aid policy goals is smaller.

This article examines how the EU's effectiveness as a mediator in peace negotiations can be appropriately conceptualized and analysed. Mediator effectiveness is analysed along two dimensions: goal-attainment and conflict settlement. Investigation of the conditions of mediator effectiveness is structured around four key sets of variables: mediator leverage, mediation strategy, coherence and the conflict's context. In our empirical analysis of EU mediation between Serbia and Kosovo (Belgrade-Pristina dialogue) we find that the medium degree of EU effectiveness (both in terms of goal-attainment and conflict settlement) can be explained by its great leverage vis-à-vis the conflict parties due to their EU membership aspirations and its strategy of a mix of manipulation and formulation that draws on this leverage to move parties toward agreement through the use of positive incentives. A limited degree of EU coherence and spoiler problems in Northern Kosovo seem to have had a constraining influence on EU effectiveness.

Under the umbrella of Capacity Building in Support of Security and Development (CBSD), the EU provides equipment and infrastructure to the armed forces of partner countries. The 2017 reform of the Instrument contributing to Stability and Peace (IcSP) to implement CBSD represents a remarkable integrative step at the interface of EU security and development policy. This article explains the IcSP reform through a neofunctionalist lens. It argues that the extension of the Commission's competences in EU security affairs can be explained by the interaction of functional and cultivated spillover pressures. Functional discrepancies between the CSDP framework and EU development policy created strong pressures for further integrative steps. Moreover, the Commission exerted strong pressures for adopting its proposal for implementing CBSD through the IcSP by drawing on a combination of strategic coalition-building, bargaining tactics and community framing. The case illustrates neofunctionalism's potential to explain external policy integration.

In their recently published JCMS article, Gezim Visoka and John Doyle have proposed the concept of 'neofunctional peace' as a means to conceptualize the EU's peacemaking practices in the case of the EU-facilitated Belgrade-Pristina dialogue. This article challenges the 'neo-functional peace' on conceptual and empirical grounds. We critically discuss Visoka and Doyle's (2016) reading of neofunctionalism and question parts of their empirical evidence given for the existence of a 'neo-functional peace'. Going beyond a mere critique of the article by Visoka and Doyle and arguing that the authors may not have fully exploited neofunctionalism's potential for theorizing EU external policy, we stipulate a neofunctionalist logic for explaining integration in the area of EU external policy. Focusing on three spillover dynamics to explain the initiation of the Belgrade-Pristina dialoguefunctional discrepancies, supranational entrepreneurship and external spilloverwe illustrate how neofunctionalism can be used to explain the extension of the scope of EU competences and action in the external policy realm. helpful suggestions on the literature.