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Thursday, 23. September 2021, 9:00 - Friday, 24. September 2021, 18:00, Heidelberg

Contested Norms of International Peace and Security Law (23-24 September 2021)



23-24 September 2021, Heidelberg

#### An updated schedule will be distributed and uploaded in July ####

Max Planck Institute for Comparative Public Law and International Law (MPIL)

Max Planck Research Group Shades of Illegality in International Peace and Security Law


Sponsored by the European Society of International Law

Convened by Christian Marxsen (MPIL) & Max Lesch (Zeppelin University)


Keynote speakers

Veronika Bílková, Institute of International Relations Prague

Ian Hurd, Northwestern University


According to a widely shared perception, we live in times of heightened geopolitical tensions and a crisis of the international system. The German and French Foreign ministers have held, for example, that the entire multilateral system, the cornerstones for international peace and security, are in the most severe crisis since the founding of the United Nations. Despite the prima facie shared crisis diagnosis, there is, however, much less agreement about the nature and consequences of the challenges for peace and security law. In historical perspective, we might even observe a lot more continuity than the crisis narrative suggests. Bringing together International Law and International Relations scholars, this interdisciplinary workshop shall unpack the crisis narrative by zooming in on the contested norms of peace and security law on three levels: Which norms are contested? Where and how do international actors voice and deal with contestation? What are the effects of these contestations on peace and security law as a whole?


1. Contested norms

Although the crisis narrative is ubiquitous, it often remains unclear which norms actually are disputed between international actors and at which level contestation takes place. On the one hand, we observe controversies about specific norms such as the right to self-defence. On the other hand, some states seem to advocate more radical approaches such as “spheres of influence” as alternatives to the universality of the UN Charter. Another possible shift could arguably be the emergence of alternative justificatory systems, such as the reference to “legitimacy” or “acceptability” as benchmarks for assessing and justifying state action, as opposed to strict standards of legality and illegality.

Which norms of peace and security law do states challenge? Is contestation limited to specific norms or do we witness a deeper-rooted contestation of the foundations of the international legal order and novel approaches to multilateralism and sovereignty? Is international law as such losing relevance as a yardstick for assessing state action?


2. Forums and modes of contestation

International actors voice contestation in different forums and through changing modes of contestation – varying in their formality, politicisation and legalisation. Arguably the last two decades saw in particular the emergence of a new practice of the Security Council which neither authorized certain interventions nor clearly labelled them as illegal. In doing so, the Security Council created a veil of ambiguity which allows states to invoke peace and security law even where no substantive consensus on concepts such as self-defence exists. Moreover, where institutions are under increasing pressure, new forms of international cooperation are likely to emerge.

In which forums does contestation take place and how are modes of contestation changing? What is the role of new modes of crisis management both within and outside existing institutions?


3. Contestation and its effects: stability, change, erosion?

The current alleged crisis of peace and security law is often equated with the weakening of its norms. Yet, the diagnosis of the death of the prohibition of force, for instance, is almost as old as the norm itself. On the one hand, contestation does not necessarily weaken peace and security law, but it can also help to foster renewed agreement and stabilise, or even strengthen, international norms. On the other hand, the establishment of new, arguably lower, thresholds prohibiting low-intensity use of force or the resort to non-legal (political/legitimacy-related) justifications might lead to hollowing out the norms of peace and security law.

Are we observing a weakening of the norms of peace and security law? Under which conditions does contestation lead to their strengthening? What are the effects of more flexible interpretations of peace and security law or non-legal and cynical justifications of the use of force?



The two-day workshop will take place at the Max Planck Institute in Heidelberg and begin on Thursday, 6 May 2021 at 11.00 am. We will provide for accommodation for presenting participants. There is limited funding available to cover travel costs. Please indicate whether you require funding when submitting your abstract. The workshop is co-organised by Christian Marxsen ( and Max Lesch (Zeppelin University, If there are any further questions do not hesitate to contact us.

For further information on the Max Planck Research Group visit


Im Neuenheimer Feld 535
69120 Heidelberg