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Foreign Relations Law


Admission requirements

Required course(s):

  • Structure and Functioning of the EU

In addition, students have to have completed at least one of the following courses:

  • Comparative Legal and Economic Integration

  • Constitutions and Constitutionalism


Who has the power to declare war? Who decides which countries receive development aid? Which ones gets hit with sanctions; which ones receive arms? Who represents you at the UN? How many members of parliament are needed to ratify a new treaty; and how many to block it? In particular, how do the European Union and its Member States organize their relations with the rest of the world?

These are all legal questions—with an undoubtedly politically sensitive dimension—that are answered by a body of law called (Comparative) Foreign Relations Law. The latter is the set legal norms that regulate a polity’s relations and interactions with the outside world. It is closely related to, but distinct from, international law. In some cases, these rules may even require non-compliance with international obligations. Foreign Relations Law includes matters such as external representation, treaty-making powers, war powers, engaging with international institutions, federalism, as well as the role of the different branches of government regarding each of these issues.

Every country has its own foreign relations law, but also supranational and international organizations have rules on their relations with the rest of the world, albeit their ability to act independently from their respective member states varies. The course explores a select number of salient substantive issues of Foreign Relations Law. While using examples from different jurisdictions around the world, most of the case will be focused on the European Union.

Course Objectives

After successful completion of the course, students are able to, in terms of knowledge:

  • Goal 1: Explain the main issues, features, concepts, and legal principles of foreign relations law;

  • Goal 2: Describe the relationship and differences between international law and a polity’s foreign relations law.

After successful completion of the course, students are able to, in terms of skills:

  • Goal 3: Compare different national frameworks of foreign relations law as well as those of supranational organizations such as the EU;

  • Goal 4: Interpret and analyze legal texts and judgments (primary sources) in the field of foreign relations law, drawing on scholarly literature (secondary sources);

  • Goal 5: Apply legal research, writing, argumentation, and presentation skills in the framework of a case problem.


Timetables for courses offered at Leiden University College in 2023-2024 will be published on this page of the e-Prospectus.

Mode of instruction

The course uses a variety of teaching methods, including lectures, student presentations and student-led, class discussion, as well as an interactive, student-led moot court. Teaching materials include primary sources (legal texts and judgments), secondary readings, and a moot court case (compromis).

Assessment Method

  • General participation; Goals 1, 2, 3, and 4 (10%)

  • Critical Debate Leadership; Goals 3 and 4 (17%)

  • Mid-term exam; Goals 1, 2, 3, and 4 (30%)

  • Moot court; Goal 5

    • 6% for preliminary analysis
    • 18% for written pleadings
    • 19% for oral pleadings

Reading list

Course textbook:

  • Ramses Wessel and Joris Larik (eds), EU External Relations Law: Text, Cases and Materials (2nd edition, Hart Publishing, 2020)

Course textbook available online via Leiden Library:

  • Curtis Bradley, Oxford Handbook of Comparative Foreign Relations Law (Oxford University Press, 2019)

Links to further compulsory readings and additional reading recommendations will be provided on Brightspace.


Courses offered at Leiden University College (LUC) are usually only open to LUC students and LUC exchange students. Leiden University students who participate in one of the university’s Honours tracks or programmes may register for one LUC course, if availability permits. Registration is coordinated by the Education Coordinator,