Public International Law I
International Law and Municipal
26 September 2013
The relationship between IL and municipal law poses two problems:
1. Theoretically, i.e. whether they form part of one universal legal order or are
two distinct systems of law; and
2. Practical, .e. how to resolve a conflict between IL and municipal law.
Relationship between International Law and Municipal Law
Two main theories that are, dualist and monist that have influenced the
constitutional law of each country as to the application of international law
by municipal courts and other domestic bodies.
IL and municipal law are two independent and separate system.
Neither legal system has the power to create or alter the rules of the other.
However, as they may regulate the same subject matter a conflict may arise
in each a municipal court will apply municipal law.
Should this cause a breach of IL then this would be a matter to be settled by
means of diplomatic protest or of a judgment of an international court.
There are many varieties of monism but its man premise is that IL and
municipal law are part of the same legal order.
As they may regulate the same subject matter any conflict between the two
would be solved in favor of IL.
Third theory: Formulated by Sir Gerald Fitzmaurice.
He argued that as the systems of L and national law do not operate in
common fields they can never come into conflict, but what occur is a conflict
of obligations, in which case the domestic law remains unaffected but a
state will, on the international scene, incur liability for a breach of an
Fitzmaurice the General Principles of International Law Considered from the
standpoint of the Rule of Law
“This controversy (between monism and dualism) turn on whether
international and internal law are two separate legal orders, existing
independently of one another-and, if so, on what basis it can be said that
either is superior to or supreme over the other; or whether they are both part
of the same order, one or other of them being supreme over the other within
It follows from the same principles that there cannot be conflict between
rules belonging to different juridical orders, and, consequently, in particular
between international and internal law. To speak of conflict between
international law and internal law is as inaccurate as to speak of conflict
between the laws from different states: in reality the existence of a conflict
between norms belonging to different juridical orders cannot be affirmed
except from a standpoint outside both one and the other.
‘The mutual independence of international and national law is often
substantiated by the alleged fact that the two systems regulate different
subject matters. National law, as it said, regulates the behavior of
individuals, international law the behavior of states. We have already shown
that the behavior of states is reducible to the behavior of individuals
representing the state. Thus the alleged difference in subject mater between
international and national cannot be a difference between the kinds of
subjects whose behavior they regulate…”
Municipal Law before the International
Courts and Tribunals
The rule is that in the event of conflict between Il and national law, IL
Draft Declaration on Rights and Duties of States
Every state has a duty to carry out in good faith its obligation arising
from treaties and other sources of international law, and it may not
invoke provisions in its constitution or its laws as an excuse for
failure to perform this duty.
The PCIJ in German Interests In Polish Upper Silesia held that the
only law which it could apply was international law. Whilst a state
cannot invoke the provisions of its internal law as justification for its
failure to perform a treaty, an international court could review the
municipal laws of one of the parties to determine to what extent the
party was observing its international obligations:
From the standpoint of international law and of the Court which is its
organ, municipal laws are merely facts which express the will and
constitute the activities of states, in the same manner as do legal
decisions or administrative measures. The Court is certainly not
called upon to interpret the Polish law as such but there is nothing to
prevent the Court’s giving judgment on the question whether or not
in applying that law Poland is acting in conformity with its obligations
towards Germany under the Geneva Convention.
A state cannot rely upon its municipal law to avoid its international
Alabama Claims Arbitration
The tribunal rejected the British argument that because its
constitutional law was not such as to provide it with the power to
interfere with the private construction and sailing of the ships
concerned, Great Britain had not violated its obligation as a neutral
in the United States Civil War by allowing the construction and
sailing to occur.
Exchange of Greek and Turkish Populations Case
Referring to Article 18 of the Treaty of Lausanne 1923, by which the
parties undertook “to introduce in their respective laws such
modifications as may be necessary with a view to ensuring the
execution of the present Convention” the Court stated:
This clause…merely lays stress on a principle which is self-evident,
according to which a state which has contracted valid international
obligations is bound to make in its legislation such modifications as
may be necessary to ensure the fulfillment on the obligation
Triquet v Bath
In this case, in which the defendant, a domestic servant of the Bavarian
Minister to Great Britain, successfully claimed diplomatic immunity, Lord
Mansfield discussed the position of international law in English law.
Lord Mansfield. I remember in a case before Lord Talbot of Buvot v Barbuit
upon a motion to discharge the defendant (who was in execution for not
performing a decree), ”because he was an agent of commerce,
commissioned by the King of Prussia, and received here as such,” the
matter was very elaborately argued at the Bar; and a solemn deliberate
opinion given to the Court. These questions arose and were
discussed...”what ways the rule of decision: the act of Parliament or the law
of nations. “That the law of nations, in its full extent was part of the law of
IL before the UK Courts
Two doctrines that are, incorporation and transformation.
Under the doctrine of incorporation, IL becomes automatically part of
municipal law without any express act of adoption, i.e. any positive act on
the part of the State.
This entails that a signed and ratified treaty becomes part of municipal law
without any need for legislation being passed to give that treaty a binding
legal effect in municipal law.
Similarly, rules of customary law will not require any implementing legislation
in order to become part of municipal law of the state concerned.
In Buvot v Barbuit the Lord Chancellor Talbot declared: ‘That the law of
nations, in its full extent is part of the law of England.’
Under doctrine of transformation, IL in order to become part of municipal law
must be ‘transformed’ into municipal law.
This requires a positive act on the part of the state consisting of enacting
domestic legislation which will give effects in municipal law to international
In R v Keyn (1876) is often cited as one which supports the doctrine of
…English court did not have jurisdiction in the absence of an Act of
Parliament granting such jurisdiction. This decision has been interpreted as
supporting the ‘transformation’ approach and as displacing the doctrine of
The current approach
Lord Denning in Trendtex Trading Corporation v Central Bank of Nigeria
confirmed the application of the doctrine of incorporation. He commented on
the relationship between customary IL and English law in the following
‘…Under the doctrine of incorporation, when the rules of IL change, our
English law changes with them. But, under the doctrine of transformation,
the English law does not change. It is bound by precedent. As between
these two schools of thought, I now believe that the doctrine of incorporation
is correct, Otherwise I do not see that our courts could ever recognize or
change the rules of IL.’
The dictum of Lord Denning in Trendtex has been followed in a number of
cases so supporting the proposition that the doctrine of incorporation has
been adopted as the prevailing principle in English law.
Various judgment in Pinochet case provide support for the doctrine of
incorporation, for example, Lord Lloyd stated that the principles of
customary IL ‘form part of the common law of England,’ whilst Lord Millet
emphasized that ‘customary IL is part of the common law.’
Certainly, the court have been reluctant to apply principles of the common
law which conflict with customary IL.
In Westland Helicopters v Arab Organization for Industrialization, Colman J
confirmed the doctrine of incorporation.
International Treaties and their relationship
with English law
With regard to treaties, dualist approach has been adopted in the UK.
When a change in domestic law is required to give effect to treaties, they
become part of English law only if enabling legislation, primary or
secondary, has been passed.
In most cases, this is done by an act of Parliament.
Malaysia’s acceptance of IL depending on the following legislations:
1. Federal constitution
2. Civil Law Act 1956
3. Membership in IGOs
5. Acts of Parliament
6. Judical decision