Making international law work on the ground: constitutional stress for national courts

International organizations, states and NGO's invest heavily in treaties and other rules of international law. National courts are crucial to give effect to these rules. But judges may be hesitant to do this, because of the way they see themselves as guardians of the constitutional separation of powers.  

The challenge: challenging constitutional rules, separating powers

Treaties and international rules are usually negotiated by diplomats from the ministry of foreign affairs, or from other ministries. This is the executive branch of government, and the legislative branch (parliaments) is not always involved. So courts may hesitate to apply international law norms in domestic cases, or take these norms less seriously then the ones coming from their national legislators.

In most countries, the application of internaitonal rules is seen as a matter of constitutional law. This research project explored how courts perceive their mandate to import international rules into a purely national context. It focused on four different legal systems: the United States, the United Kingdom, France, and the Netherlands. 

The results

Every constitutional and legal system has its own way to respond to international law. Political, social, and historical forces combined produce different tolerances in the scope of powers exercised by judicial, executive, and legislative organs, and in their mutual equilibrium.

However, courts are cautious in exercising their constitutional powers. They prefer an explicit constitutional provision for recognising international law as national law. In other cases, international law is treated as a non-binding aspirational standard.

Implications for "sponsors'  of international law

Generally, national judges  feel they have at least some discretion whether to accept international rules or not. International organizations, states or NGO's that want to see international rules implemented in the national legal orders should not assume that their international norms will be easily domesticated. They may have to think about ways to: 

  • Make sure these norms are turned into national legislation
  • Design their rules in such a way that they can be easily incorporated into the national legal texts
  • Influence how judges view international law, by participating in the debate about the constitutional status of international rules 
  • Show and explain to judges that their laws have added value and bring more equitable results compared to what the national rules have to offer

Project details

Project leader: Prof. Dr. Leonard Besselink
Duration: 2007-2011