The EU acts as one of the most powerful economic actors in the global economy, presents itself as the most successful integration project in recent history, and deploys one of the largest diplomatic services in the world.

The Master’s in European Union Studies at Leiden University offers students an opportunity to study the EU from multiple disciplinary perspectives.

Are you thinking about studying European Union Studies? Learn more and watch the introduction video.

How to explain the apparent high success rates of the EU infringement procedures, which are the major tools for enforcing EU law, against the member states?

What political factors affect the speed or duration of EU legislative decision-making?

This special issue of the Journal of European Policy presents results from the research on the European Union Enlargement and its Integration Capacity. The Journal of European Public Policy is one of the leading journals in this field.

How do crises produce changes in specific European Union foreign policy areas, and how should we conceptualise these policy changes?

The researchers examine the Council of the European Union's voting behaviour between 2010 and 2021 and the impact of different independent variables.

This thesis examines the complexity of legislative decisions within the EU, with a specific focus on the Council of the EU.

Madeleine O. Hosli, Professor of International Relations, wrote this book in which she analyses the complex relations between the European Union (EU) as a regional organization and the United Nations (UN) as an international, global governance institution.

The Law of the European Union is a complete reference work on all aspects of the law of the European Union, including the institutional framework, the Internal Market, Economic and Monetary Union and external policy and action.

The Summer School ‘The European Union, the United Nations and Global Governance’ will focus on a range of topics relevant to interactions between the European Union (EU) and the United Nations (UN) and the EU’s role within current patterns of global governance.

This project investigates the capacities of EU institutions to coordinate the responses of member states to critical events.

This research paper was requested by the European Parliament's Committee on Civil Liberties, Justice and Home Affairs. It was published by the International Centre for Counter-Terrorism (ICCT) in The Hague. Leiden University is one of the participating institutes in this publication and our researcher…

Our project focuses on the analysis of decision-making processes in the European Union (EU) and explores how approaches and tools to understand decision-making found in both the Natural and the Social Sciences can be linked, knowledge between these traditions exchanged and synergies utilized. To explore…

This article presents a new dyadic approach to studying voting behaviour in the Council of the European Union.

When EU member states signed the Treaty of Lisbon in 2007, they did not anticipate the manifold crises in store for them over the following years. Instead of the intended consolidation of a Union which had just gone through its most profound modernisation and biggest round of enlargements, the EU has…

The coronacrisis makes painfully clear that a transboundary crisis requires a transboundary response. The European Union could play a key role, but that has not happened so far. Political scientist Amy Verdun (Leiden University) explains why.

The article examines how Southern European member states' newspapers portray European irregular migration governance.

What drives public agencies’ propensity to engage in more extensive practices and/or to initiate more far-reaching mechanisms of accountability than those mandated by law? In other words, what are the drivers of voluntary accountability?

Madeleine O. Hosli & Jaroslaw Kantorowicz analyze EU states' foreign policy divergence at the UN General Debate, assessing if Lisbon Treaty reforms increased EU cohesion or if states maintain distinct positions.

The Department of Child Law collaborated on a study on missing children in the European Union for the European Commission. The outcomes of the study aim to help to improve the mechanisms involved when children are missing in EU Member States.

This article studies the influence of framing on preferences for cooperation with the EU.

Dr. Gruni published an article on the impact on sustainable development in the EU Common Commercial Policy of recent Opinion 2/15 CJEU on the Global Trade and Customs Journal.

Matthias Haentjens, Jouke Tegelaar and Dorine Verheij have recently published the chapter Financial Market Regulation and Supervision in the new volume of the prestigious The Law of the European Union (previously Kapteyn and VerLoren van Themaat).

How do processes of coalition-formation influence patterns of decision-making in the European Union?

The European Council and the European Commission have a similar role in agenda setting. Both place issues on the EU agenda. However, these institutions have distinct designs. They have different political attributes (the European Council has considerably more political authority) and information-processing…

On 7 May, Aleksandre Zardiashvili defended the thesis 'Power and dignity: the ends of online behavioral advertising in the European Union'. The doctoral research was supervised by Bart Custers and Simone van der Hof.

This book, written by two representatives of Leiden Law School, describes the framework of the European Insolvency Regulation (recast) (‘EIR Recast’), in force since June 2017.

This paper investigates possible convergence of issue salience of terrorism among citizens within the European Union for ten jihadist attacks in the period 2015–2017 using Eurobarometer survey data.

As a research project between four Jean Monnet Chairs - two located in Europe, one in Canada and one in the U.S. -- the project DEUBAL has been approved in 2010 for co-financing by the European Commission. DEUBAL aims to study changes in European decision-making due to the Lisbon Treaty, by a combination…

Eva Michaels & Monika Sus examine strategic autonomy in EU foreign policy, tracing evolution from the 1998 Saint-Malo Declaration to its current focus.

Eva Michaels & Monika Sus examines European Strategic Autonomy (ESA) as the EU’s response to the fragmentation of the Liberal International Order.

Introducing five papers about of the impact of crises on the governance, decision-making, and institutional design of the Euro Area, political scientists Valerie D'Erman (University of Victoria, Canada), Paul Schure (University of Victoria, Canada) and Amy Verdun (Leiden University) summarise the 'lessons…

Müller, Braun & Fraussen examine the conditions under which commissioners appear in the news and which communication strategies they pursue.

The corona crisis is also a disinformation crisis for the global community in general, and for the European Union (EU) in particular. What is less clear is how adequate the EU’s response to the ‘infodemic’ has been. This essay exposes the dangers of disinformation for the EU, which have intensified…

How can the problems in establishing a sustainable common security and defence mechanism for the EU be explained?

On 23 juni 2019, Zygimantas Juska defended his thesis 'The Role of Collective Redress Actions to Achieve Full Compensation for Violations of European Union Competition Law'. The doctoral research was supervised by Prof. dr. T.R Ottervanger.

The refugee crisis and terror threats call for better European cooperation, was the message from Piet Hein Donner in his Cleveringa lecture on 26 November in the Academy Building. ‘Opting for an open and pluriform community takes courage.’

How many of our laws in the Netherlands are actually determined by the European Union? In many areas, the influence of the EU has increased. But 80 per cent – a figure referred to in 1989 by then European Commission President Jacques Delors – is a very wide estimate. Research from around 15 years ago…

A month after the event, we can say the inaugural lecture of Prof. Luuk van Middelaar on “The European Union and the politics of events”, on 23 September 2016, has obtained good coverage in the Dutch national media.

How can we understand the implementation of EU policy and what challenges are involved?

In this article, Madeleine O. Hosli and Wen Pan examine how intergovernmental dynamics shaped the European Stability Mechanism, using Liberal Intergovernmentalism to assess negotiation phases, the influence of major member states, and which theoretical assumptions hold or need qualification.