International law abounds with treaties; yet effective implementation and compliance are recurring challenges. Developing a new treaty is one matter, but helping ensure that the parties will give it effect is another. There may be the potential for international legal proceedings if a dispute arises, but there are other and arguably perhaps better ways to intervene and bring about conduct consistent with treaty obligations. In recent years, many international treaties have established ‘in-house’ non-compliance mechanisms (NCMs) or other treaty bodies to help bring about implementation and promote parties’ compliance with their obligations.
NCMs differ from International Courts and Tribunals (ICTs) because they can be triggered without the formal initiation of legal proceedings, their procedures are non-adversarial, and there is in most cases an absence of punitive sanctions. Implementation and compliance committees are best known in international environmental law. Multilateral environmental agreements (MEA) with established NCMs include, for example, the Montreal Protocol, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, the Paris Agreement, the Basel Convention, the Minamata Convention, the Aarhus Convention, the Escazú Agreement and the Espoo Convention. The Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement) may be the latest.
In our edited book International Courts versus Non-Compliance Mechanisms: Comparative Advantages in Strengthening Treaty Implementation (Cambridge University Press, 2024), we show that even beyond the environmental field, highly developed NCMs are now found across a wide spectrum of international law. For instance, NCMs are found in the fields of trade, finance, disarmament, international criminal law, humanitarian and human rights law, as well as the law of the sea. Meantime, NCMs within international environmental law have continued to evolve, losing their hard quality and becoming increasingly facilitative, that is, promoting implementation of and compliance with treaty provisions. MEAs’ NCMs have also become more sophisticated, taking on new processual elements such as that seen in the UNECE Water Convention, where any party may now seek an advisory opinion.
NCMs operate alongside ICTs
All these ‘quasi-judicial’ NCMs are designed to exist alongside formal dispute resolution processes, including through international courts and tribunals. Yet, their functions in some cases overlap, ranging from inquiring into parties’ compliance challenges and providing suggestions for addressing them, to clarifying treaty obligations and providing authoritative interpretations, to the resolution of disputes between parties. NCMs’ work produces a significant spectrum of effects, including through fact-finding. There are also new ways in which existing mechanisms may be used, for instance through the state-to-state triggering of NCMs. NCM proceedings may be pursued either in place of or alongside proceedings in ICTs.
NCMs and ICTs: Why might NCMs work best?
In some cases, formal dispute resolution processes work best to ensure treaty compliance; in other cases, NCMs are more effective. Compared to judicial processes, NCMs need more follow-up, decision-making is less timebound and their outcomes are not legally binding. However NCMs have the advantage of being quicker and less expensive, helping avoid costly long-running disputes. They promote co-operation and provide access to support and constructive engagement in solving the compliance issue at stake. For these reasons, the use of informal NCMs may be more effective in helping to bring states into compliance with their treaty obligations or to address situations of non-compliance than recourse to an ICT for breach of a treaty.
Non-compliance mechanisms operate in complementarity and in synergy with ICTs, as well as with other NCMs. The relationship between NCMs and between NCMs and ICTs is a fascinating topic, including the cross-referencing and communication between NCMs and ICTs and between NCMs. There is significant potential for parties and complainants to engage in strategic litigation, but also a danger of ‘forum shopping’. Civil society actors have learnt how to use both NCMs and ICTs in sequence with one another for best effect in some areas, such as wildlife conservation.
NCMs’ legitimacy depends on both their processes and outputs
Legitimacy can mean that there is a fair process, and it can also mean that the decisions and practical or legal effects are legitimate in terms of their content. Procedural legitimacy is a foundational requirement for facilitative compliance and it includes questions around consent, participation, representation and reliance on NGOs and human rights organizations, including problems with funding, technological organization and capacity but also mandate, legitimacy and selective political orientation, representation by lawyers, the independence of the members of NCMs, the independence of secretariats supporting them, the role of scientific bodies, the need for technical expertise and assistance, public involvement and the provision of triggering information. As to content or “output” legitimacy, NCMs may offer certain opportunities to help prevent harm through early intervention, and by encouraging greater efforts at treaty implementation, where an ICT would be in a position only to help with the remedying of harm retrospectively. Further factors enhancing the substantive legitimacy of recourse to NCMs include the multilateral institutional context in which they operate and their character as vehicles for the stewardship of common versus individual interests.
NCMs are valuable where there are shared international legal interests
Our book shows that where legal interests are shared among States e.g., global public goods/ common concerns, it may be more instrumental to employ a process in which all with a legal interest have a degree of ownership rather than more narrow and confrontational litigation or arbitration. The various chapters in our book on health, watercourses, international economic law and international criminal law confirm that “non-compliance machinery” is particularly well suited and important for addressing broadly shared international legal interests affecting common concerns and global public goods.
Both NCMs and NCTs offer valuable opportunities
The many questions around recourse to international courts versus non-compliance mechanisms respectively to advance state compliance with international treaties are complex. However ultimately both NCMs and ICTs offer legitimate and valuable diverse modes and means to help bring about treaty compliance.
About the authors
Caroline Foster is a professor of international law at the Faculty of Law, University of Auckland, New Zealand and Director of the New Zealand Centre for Environmental Law. Her latest book is Global Regulatory Standards in Environmental and Health Disputes: Regulatory Coherence, Due Regard and Due Diligence (Oxford University Press 2021).
Christina Voigt is a full professor of law at the Department of Public and International Law, University of Oslo, Norway; Chair of the IUCN World Commission of Environmental Law; and Member of the Council of the IUCN. She works on legal issues of climate change, biodiversity conservation, environmental multilateralism and sustainability.
This think-piece is based on the authors’ edited volume International Courts versus Non-Compliance Mechanisms: Comparative Advantages in Strengthening Treaty Implementation (Cambridge University Press, 2024).