Reception of International Law in Domestic Law

• Author: John H. Currie
• Pages: 218-264

CHAPTER 6

RECEPTION OF

INTERNATIONAL LAW

IN DOMESTIC LAW

A. THE INTERNATIONAL/NATIONAL

LAW INTERFACE

Having reviewed the origins, nature, subjects, and sources of inter-

national law, it is now appropriate to consider the international legal

system’s interaction with national, or domestic, legal systems. What is

the connection, if any, between international and domestic law? Does

international law, which is primarily concerned with regulating the

conduct of states, have domestic legal effect within states? Does it cre-

ate rights and obligations for sub-national actors such as individuals,

corporations, and government organs? If so, how and why?

To inquire into the effects of one legal system on or in another is, of

course, to ask a legal question. Its answer will depend on rules that de-

termine, as a matter of law, how one legal system treats another. Given

that a single subject or situation will potentially be governed by more

than one system of law, most, if not all, legal systems have developed

such rules to address these situations of potential overlap and conf‌lict.

These rules often dictate which system of law will apply or “trump”

in particular circumstances, although sometimes such rules will avoid

the conf‌lict by variously aligning the two legal systems for the purposes

of resolving a particular problem.

Given that each legal system may be expected to develop its own

set of rules for regulating its interaction with other legal systems, it is

218

Reception of Inter national Law in Domestic L aw219

evident that one cannot determine, in the abstract, the way in which

legal systems will interact. Rather, the answer to the question “how will

legal systems A and B interact?” will depend on whether one is asking

the question from within the framework of legal system A — complete

with its rules governing interactions with other legal systems — or

from within the framework of legal system B — again, with its own set

of rules governing interactions with other legal systems. Each legal sys-

tem may develop incompatible rules for resolving which system of law

applies in what circumstances, giving rise to the potential for yet fur-

ther conf‌lict. The point, however, is that how two or more legal systems

will interact will vary depending on which legal system’s rules for re-

solving this issue are applied; that is, on one’s legal frame of reference.

Transposing this to the relationship between international and do-

mestic legal systems, the nature of that relationship will thus depend

on whether one is considering the issue from the perspective of inter-

national or domestic law. For example, we have already seen a number

of instances where an international legal rule is deemed by internation-

al law to prevail over a conf‌licting rule of domestic law.1 This does not,

however, prejudge the answer that might be given to the same question

by the relevant domestic legal system. Considering the issue from that

perspective, it might well be that international law would be consid-

ered subordinate to the dictates of the domestic legal system.

Moreover, while there is only one international legal system, there

are nearly two hundred national legal systems (not to mention those

operating within federal units which make up federal states) and thus

the nature of the interaction between international and domestic law

will potentially vary with each such national or domestic legal system.

While one domestic system might, as above, deem a conf‌licting rule of

international law to be subordinate to the domestic legal rule, another

might yield entirely to the international rule. It all depends on the rules

of interaction adopted by each domestic legal system.

1 For example, the ru le of treaty law providing t hat domestic legal impedi ments

are no excuse for fa iling to perform a bindin g treaty obligation: see Ar ticle 27

of the Vienna Convent ion on the Law of Treaties, 23 May 1969, 1155 U.N.T.S. 331

(entered into force 27 January 1980) [Vienna Convent ion] and discussion in

Chapter 4, Section G(1). Of course, it will not alw ays be the case that inte r-

national la w deems its rules to overr ide conf‌licting domestic norm s. There are

instance s in which even internation al law subordinates its elf to the dictates of

domestic legal sy stems. For example, the legal per sonality of political or ter ri-

torial unit s such as provinces wit hin federal states depend s, in the internationa l

legal system, upon whet her and to what extent these u nits are entitled under

the domestic con stitution to conduct their own foreig n affairs.

PUBLIC INTERNATIONA L LAW220

It would of course be a monumental task to try to describe the rules

governing the relationship between every domestic legal system and

international law. However, it is possible to describe here two broad

theoretical models that have been advanced to explain, or argue for,

the appropriate relationship between international and domestic legal

systems. We will see that, in the present practice of states, elements of

both theoretical models are present. We will then turn to consider in

some detail, by way of illustration, the particular rules developed by

the Canadian legal system to govern its own relationship with inter-

national law. It bears repeating, however, that those rules are peculiar

to the Canadian legal system and do not necessarily apply to the rela-

tionship between other domestic legal systems and international law.

B. PRINCIPAL THEORETICAL MODELS 

DUALISM vs. MONISM

While there are many ways of theorizing about the interaction between

international and domestic legal systems, the two main theoretical

models developed by international lawyers are known as “dualism”

and “monism.”2

The f‌irst of these, dualism, was championed by such international

legal philosophers as Hegel.3 As its moniker suggests, this model focus-

es on the peculiar nature of the international legal system and draws

a rigid distinction between it and domestic legal systems. In its purest

form, dualism emphasizes that international and domestic law govern

distinct subjects, regulate discrete subject matter, and emanate from

different sources. Dualism posits that international and domestic legal

systems exist in complete legal isolation from one another. Neither is

superior to the other such that, in the event of a conf‌lict between the

2 For a concise overv iew of the monist-dualist debate a mong international

lawyers gener ally, see G. Fitzmaurice, “The Genera l Principles of Internat ional

Law: Consider ed from the Standpoint of the Rule of L aw” (1957-II) 92 Rec. des

Cours 5 at 68– 85.

3 G.W.F. Hegel, Natural Law: The Scientif‌ic Ways of Treating Law, its Place in Moral

Philosophy, and its Relation to the Positive Scie nces of Law, trans. by T.M. Knox

(Philadelphia: Un iversity of Philadelphia Pre ss, 1975); see also L . Oppenheim,

Internati onal Law: A Treatise, vol. I, 8t h ed. by H. Lauterpacht (London: Long-I, 8th ed. by H. Laute rpacht (London: Long-

mans, 1955) at 37–39; K. Strupp, “Règles générales du d roit de la paix” (1934-I)

47 Rec. des Cours 263 at 389– 418.