Municipal Law and International Law

Relationship between Municipal Lawand International Law
• Nature of relationship that exist betweeninternational law and national law
• Important theoretical framework :
– Monism and Dualism
• In case of a dispute between national and international law, which is to prevail ?

• views international and national law as two separate systems that exist independently of one another
• international law and municipal legal systems constitute two distinct and formally separate categories of legal orders
– differ as to their sources
– Differ as to the relations they regulate
– And legal content
• these two systems are seen to be firmly independent from one another, as neither can claim supremacy
• From a practical perspective, if a national court in a dualist state is considering a case and there is a conflict between international and national law, the court (in the absence of any legislative guidance to the contrary) would apply domestic law.

• monist theory, developed by Kelsen
– theory of Grundnorm
– all legal rules (including international rules) derive their validity from a basic rule or Grundnorm (he considers international law as Grundnorm)
• there is a relationship between national and international law, with international law being supreme
• as law ultimately regulates the conduct of individuals, there is a commonality between international and national law which both ultimately regulate the conduct of the individual
• the assertion by Lauterpacht – that only by reference to a higher legal rule can the fundamental principle of the equality of states be achieved.

Example by Brownlie
• An alien vessel may be arrested and the alien crew tried before a municipal court of the arresting authority for ignoring customs laws.
The municipal law prescribes a customs enforcement zone of x miles. The defendants argue that international law permits a customs zone of x–4 miles and that the vessel, when arrested, had not yet entered the zone in which enforcement was justified under international law
• Should national law or international law apply in such a dispute?
– Applying a dualist approach, domestic law would apply;
– applying a monist approach, international law should prevail.
– Either approach would lead to a very different practical outcome for the alien crew in this instance.
Fitzmaurice and Rosseau Approach
• argue that international law and national law lack a common field of operation
– Never operating in the same sphere
– Or, dealing with the same subject matter
• Therefore, do not come into conflict as system
• Besides, it is not the problem of conflict between municipal and international law.
– It is a question of fulfilling obligations under both sets of law.
– Domestic violation can even lead to international responsibility.
Supremacy of International Law
• Art. 27 of VCLT, 1969
– Breaches of international law cannot be justified by reference to a state’s own internal laws
• Greco-Bulgarian Communities case (1930)
– It is a generally accepted principle of international law that (…), the provisions of municipal law cannot prevail over those of the treaty
• Also reiterated in Free Zones case (1932),
Applicability of the Obligation to Arbitrate case
Use of National Law by International
Courts & Tribunals
• Do not act so as to hear an appeal
• courts have shown a willingness to borrow relevant national law concepts to apply within the international sphere
• Article 38 of ICJ Statute (discussed in second half of lecture)
• Barcelona Traction case, court used domestic law as important element to resolve the dispute
– where domestic law rules are imported, they cannot be modified or altered in the process of applying them to
international disputes
• International treaty may sometime refer domestic law: in case of nationality, national treatment etc.