By TWAGIRAMUNGU Michel

From RWANDA

"Relationship between international custom and international convention"

Abstract

The relationship between treaty and custom is a topic of great importance in practice and theory. An attempt at unraveling the intrigues involved in this relationship requires an understanding of the formal nature of the two sources of treaty and custom, and of the impact they exert upon each other in the search for applicable law in a concrete situation by government officials, judges and legislators. The separateness of these two sources is at times not clear, but shall always be maintained. Rules derived from both sources contribute to the body of international law, and they are rules of equal force. The rules thus derived from them may restrict each other in application and conflict in content, thus being conducive to strangeness in law, and may become asymmetrically opposed.
This brief description reveals the relationship between treaties and international custom which can influence international practices. That influence can result in different significant consequences for international relations as a whole.
This work is concerned with the relationship between treaty and custom at the international level.

Introduction

There is still no consensus among academics and other interested parties as to what international law is. However, Prof. J. G. Starke has stated that: “International law consists of a system of laws, the majority of which applies to states but also regulates activities of individuals and international organizations when it becomes the concern for the international community”.
There are several sources of international law, including international conventions, whether general or particular establishing rules expressly recognized by contesting states; custom, as evidence of a general practice accepted as law; general principles of law recognized by civilized nations; judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law, unilateral acts of international organization and soft law. Together with treaties, international customary law is one of the main sources of international law.

International law evolves with an everlasting entanglement of its two main sources, while conferring equal authority upon rules derived from these two sources. The issue of the relationship between both sources across and within different subject matter areas is a contentious point in real and practical sense.

While the relationship between treaties and custom is a constant in international law, there is strong sense in insisting that the two sources maintain separate existences. The question of the extent to which treaty rules, may affect the international customary rules, and vice versa, is dealt with in this work.

Chapter one: International custom
1.1. Definition

International customs are defined as evidence of a general practice accepted as law. Custom must be distinguished from mere usage, such as behaviour which may be done out of courtesy, friendship or convenience rather than out of legal obligation or a feeling that no compliance would produce legal consequences. The first requirement for the establishment of custom is the existence of a general practice in the relations between states. A general practice needs to be of consistent or habitual nature for it to be recognized as such. Consistency in this sense means an existing frequency of repetition, as well as a time period over which the practice has occurred between states.

The second requirement is the existence of belief of legal obligation on the part of the acting stated underlying that practice. This required legal belief is better known by its latin description “opino juris sive necessitatis”.

1.2 Elements of international customary law

International customary law derives its law hallmark through the possession of two elements: the objective one, material (consuetudo) and the subjective one, psychological (opinio juris) elements.

1.2.1 Material element (Consuetudo)

The material element refers to the behaviour and practice of states. International custom derives from previous practices be it positive or negative. These practices must have a certain extent, certain length of time and prove evidence of state practice.

1.2.1.1 Duration of practice

The duration of practice was highlighted by the International Court of Justice in the north sea continental shelf cases in which it stated that: “although the passage of only a short period of time is not necessarily, or of itself, a bar to the formation a new rule of customary international law…an indispensable requirement would be that within the period in question, short thought it might be, state practice… should have been both extensive and virtually uniform in the sense of the provision invoked, and should moreover have occurred in such a way as to show a general recognition that a rule of law or legal obligation is involved”.

In the light of the above, there is no set time limit and no demand that the practice should be engaged in since time immemorial. The fact that practice has been engaged in only for a brief period of time will not be in itself be a bar to the formation of customary rule, provided that the other requirements of custom are met. The length of time required to establish a rule of customary international law will depend upon other factors pertinent to the alleged rule.

1.2.1.2. Extent of state practice

The International Court of Justice in the Asylum case held that before state practice could be acknowledged as law, it had to be in accordance with a constant and uniform usage practised by the states in question.

However, the question is to know the number of state that must be involved in a particular activity before the practice is accepted as law.
ICJ statute speaks not of universal practice, but of general practice. A practice can be general even if it is not universally followed, and there is precise formula indicating how widespread a practice must be. What is of more importance than the number of states involved is the attitude of those states whose interests are actually affected.

1.2.1.3. State practice

For the purpose of establishing customary international law, treaties, diplomatic correspondence, statement by national legal advisers in domestic and international forum are amongst the indicators of state practice. Unfortunately, the evidence of state practice is not as available as it should be to permit considered opinions on many questions of customary international law. Much of it (diplomatic correspondence and other confidential government papers), is subject to rules

1.2.2. Psychological element (Opinio juris)

Practice in itself does not establish custom. An alleged rule of customary international law has to manifest not only a material element, but also psychological element known as “opinio juris sive necessitatis” often shortened “opinio juris”.
The psychological element is the subjective conviction held by states that the behaviour in question is compulsory and not discretionary. Opinio juris was introduced as a legal formula in an attempt to distinguish legal rules from mere social usage, and it refers to the subjective belief maintained by state that a particular practice is legally required of them. In the word of International Court of Justice, “…not only must the acts concerned amount to a settled practice, but they must be also accompanied by the opinio juris sive necessitatis. Either the state taking such action or other states in a position to react to it must have behaved so that their conduct is evidence of a belief that this practice is rendered obligatory by the existence of a rule of law requiring it. The need for such a belief is implicit in the very notion of the opinio juris”.

Chapter two: International conventions
2.1. Definition

Treaty is defined as an international agreement concluded between states in written form and governed by international law, whether embodied in single instruments or in two or more related instruments and whatever its particular designation. Treaties play the role of contracts between two or more state parties, such as an extradition treaty or a defense pact. Treaties can also be used to regulate a particular aspect of international relations, or form the constitutions of international organizations. The nature of a treaty is either bilateral or multilateral. Treaty is a generic term used to embrace conventions, agreements, arrangements, protocol, and exchange of notes. Treaty whether bilateral or multilateral, creates legally binding obligations for the states that are party to the treaty.

2.2. Treaties-making competence

Not all written agreements necessarily establish binding obligations. The UN charter provides that every treaty and international agreement entered into by any member state and, unless a treaty or international agreement is registered, it cannot be invoked before any organ of the United Nations. Registration in the secretariat on the UN provides tangible evidence that the agreement is to be regarded as a treaty and that is the intention of the parties concerned.

Arrangements for the exercise of a state’s treaty-making powers are left to each state in the constitutional requirements with respect to the ratification of treaties vary widely. According to Vienna Convention, a State may not invoke the fact that its consent to be bound by a treaty has been expressed in violation of a provision of its internal law regarding competence to conclude treaties as invalidating its consent unless that violation was manifest and concerned a rule of its internal law of fundamental importance.

A state representative may conclude a treaty on behalf of a state if he possesses “full powers”, or if from the practice of the states concerned or from other circumstances, it can be deduced that he enjoys full powers.
In this context, full powers refer to a document emanating from the competent authority of a State designating a person or persons to represent the State for negotiating, adopting or authenticating the text of a treaty, for expressing the consent of the State to be bound by a treaty, or for accomplishing any other act with respect to a treaty.

In addition, heads of state, governments and foreign affairs ministers are regarded as possessing by virtue of their office “full powers”
2.2.1. Adoption and confirmation of the text of treaty

The adoption of the text of a treaty takes place by the consent of all the States participating in its drawing up except as provided in paragraph two below.

The adoption of the text of a treaty at an international conference takes place by the vote of two thirds of the States present and voting, unless by the same majority they shall decide to apply a different rule.

The state may express its consent to be bound by a treaty in a variety of ways, either by signature, by exchange of instruments constituting a treaty, by ratification, acceptance or approval, by accession or by exchange or deposit of instruments of ratification, acceptance, approval or accession.

2.2.2. Observance and application of treaties

Every treaty in force is binding upon the parties to it and must be performed by them in good faith. “Pacta sunt servanda” is the maxim which expresses this basic canon of treaty observance.
As a rule, treaties do not have retroactive effect. If they to have such effect, this will be expressly stated.

2.3. Treaty interpretation

As a general rule, there are three main approaches in international law to treaty interpretation: * The objective approach of interpretation in accordance with ordinary use of the words of the treaty; * The subjective approach of interpretation in accordance with the intention of the parties to treaty; * The teleological approach of interpretation in accordance with the treaty’s aims and objectives.

2.4. Third states

As a principle, “Pacta tertiis nec nocent nec prosunt” that is, a treaty does not create either obligations or rights for a third state without its consent. The non party is bound, not by the treaty, but rather by customary international law.
2.5. Amendment and modification

Both amendment and modification relate to a revision of treaty terms by parties. Amendment is the more formal process involving at least, prima facie, all parties to the treaty, while modification is a “private arrangement” between particular parties and in respect of particular provisions.

In bilateral treaty, amendments are straightforward, but in multilateral treaty, the agreement of all state to a proposed amendment may be difficult to secure. Vienna convention on treaty lays down the procedure which, if not provided by the treaty is to be followed.
Vienna convention allows two or more parties to a multilateral treaty to conclude a modifying agreement between themselves, provided that the possibility of modification is recognized by the treaty, is not prohibited by the treaty and does not affect the right of other parties or does not relate to a provision, derogation from which is incompatible with the effective execution of the object and purpose of the treaty as a whole.
2.6. Validity of treaties

The Vienna convention stipulates five grounds on which the validity of an agreement may be challenged; non-compliance with fundamental municipal law requirements, error, fraud and corruption, coercion and jus cogens.

2.7. Termination of treaty

A treaty may be terminated as provided by the treaty or by the consent of the parties. Material breach of one of the parties may also terminated or suspend a treaty as may a supervening impossibility or a substantial change in circumstances.

2.8. Consequences of invalidity, termination or suspension

Vienna convention stipulates that a treaty which is established as invalid is void. The provisions of a void treaty have no legal force. If however, acts have been performed in reliance upon such a treaty.

* Each party may require any other party to establish as far as possible in their mutual relations the position that would have existed if the acts had not been performed; * Acts performed in good faith before the invalidity was invoked are not rendered unlawful by reason only of the invalidity of the treaty.

However, the above does not apply with respect to the party to which the fraud, the act of corruption or coercion is imputable.

2.8.1. State succession

The principle of “clean-slate” is favoured with respect to successor states, that is, a state is not to be tied by its predecessor. The obligations maintained by a state’s predecessor by way of multilateral or bilateral agreements are not automatically incumbent on a new state. A state has the option of assuming the multilateral treaties of its predecessor. The continuance of bilateral treaty depends upon agreement, either express or implied, between the parties, that is, the succeeding state and the other contracting state.

Chapter three: Relationship between international custom and international Conventions
3.1 Introduction

Treaties, international conventions, irrespective of the nomenclature, are basically the same, and are born out of agreement between States. Therefore, treaty and international custom form distinct, interrelated sources of international law, however the relationship between them appears esoteric as the Vienna Convention does not include any rule of application of customary norms in relation to a particular treaty; rather, this interaction is to be dealt with as a matter of interpretation.

3.2. Treaties as custom

Some treaties are the result of codifying existing customary law, such as laws governing the global commons, and jus ad bellum. Historically, the just war tradition represents the effort of Western cultures to regulate and restrain violence by establishing widely recognized rules of combat. Moral justification for war has its roots in Christian theology and the writings of St. Thomas Aquinas.

Jus ad bellum is defines the legitimate reasons a state may engage in war and focuses on certain criteria that render a war just. The principal modern legal source of jus ad bellum derives from the Charter of the United Nations, which declares “All members shall refrain in their international relations from the threat or the use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the purposes of the United Nations”; In addition to that, “Nothing in the present Charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a Member of the United Nations.

Together, traditional rules of combat and moral ideals have helped to form the rules of warfare found in international law. The set of guidelines commonly known as the "war convention" is made up of these moral norms and legal precepts.

Most multilateral treaties fall short of achieving universal degree of formal acceptance, and are dependent upon their provisions being regarded as representing customary international law and, by this indirect route, as binding upon non-parties.This is possible in a number of ways:

* It may be declaratory of a custom at the time when the provision is adopted; when the treaty rule reproduces an existing rule of customary law, the rule will be clarified in terms of the treaty provision. * It may crystallize custom as States agree upon provisions to be adopted during drafting; when a customary rule is in the process of development, its incorporation in a multilateral treaty may have the effect of consolidating or crystallising the law in the form of that rule. Rules contained in a treaty will also be binding as a matter of customary law if the treaty is codificatory of customs, or if the treaty has crystallized emergent rules of customary law, or the treaty forms the foundation for the passage of its provisions into customary law through the normal process of general practice. Here, treaties become sources of material or evidence in support of a potential rule of international custom.

* It may serve to generate a rule of customary law by subsequent State practice; even if the rule is new, the drafting of the treaty provision may be the impetus for its adoption in the practice of states, and it is the subsequent acceptance of the rule by states that renders it effective as part of customary law. If a broad definition is adopted of state practice, the making of a treaty would fall within the definition. Alternatively, it is possible to regard the treaty as the final act of state practice required to establish the rule in question, or as the necessary articulation of the rule to give it the opinio juris of customary international law.
It is a fact that international custom and international convention, though different, remain entangled in most of the cases. As far as a treaty rule is concerned, it plays the role of freezing custom in a document.
The rationale behind this statement is that the very rule that make treaties binding upon their parties is one of customary law, and treaties reflect or generate customary law. Even where treaties create new law, the law so created by the treaties will undergo a process of transformation into customary law to become law in the true sense of the word.
It follows that treaties of all kinds normally contribute to the proof or making of custom. The content of customary law in this context is mainly concerned with substantive provisions of a treaty. Furthermore, customary international law exists alongside treaty law. They do not, therefore, supplant or subsume each other.

3.3. Interaction between treaty and international custom

The Vienna Convention includes no rule of application of customary norms in relation to a particular treaty. Rather, this interaction is to be dealt with as a matter of interpretation under Vienna Convention.

A treaty is to be interpreted "in good faith in accordance with the ordinary meaning to be given to its terms . . . in their context and in the light of its object and purpose. It also provides guidance as to contextual material and stipulates that there shall be taken into account, together with the context, subsequent agreement regarding interpretation, subsequent practice and any relevant rules of international law applicable in the relations between the parties. This formulation of integration is broad enough to include customary rules. It emphasizes both the unity of international law and the sense in which rules should not be considered in isolation.

The language used by Vienna Convention establishes a number of parameters. The first point is that for a customary norm to be taken into account in interpreting a treaty, it must be relevant and it must be applicable. It should be related in some way to the treaty norm being interpreted and it must be legally binding upon the parties disputing the interpretation to be given to a particular treaty.

3.4. The status of treaties and custom under Article 38 of the ICJ Statute

The status of treaties and of custom, in terms of the comparative importance of those sources in international law, is not specified in ICJ Statute. It is generally recognized as a statement of sources of international law, without its applicability being limited to the order mentioned therein. The enumeration is not designed to reflect a hierarchy, and the order in which the sources of law are listed in the provision is not meant to be rigid.
Briefly, there is no a priori hierarchy between treaty and custom as sources of international law. However, in the application of international law, relevant norms deriving from a treaty will prevail between the parties over norms deriving from customary law, however, peremptory rules of customary law (jus cogens) override treaties.
The concept of jus cogens is referred to the body of peremptory rules of international law, recognized as such by the international community, admitting of no derogation and which can only be changed by another rule having the same character. Its content is controversial. If a subsequent treaty runs counter to an existing rule of jus cogens, it is null and void.

3.5. Difference between international convention and international custom

As it can be observed, customary international law is slow in its law making process and also lack of precision as it is based on a generality rather than universality of practice. Often, it is difficult to ascertain the exact content and meaning of international custom. Therefore, different States may interpret them in different ways. However, treaties are both faster in the law making process and precise in their nature. Unlike customs, whenever States feel the requirement of new rules, they may enter into treaties. These features have made the treaty law more important than customary law.

3.6. Local perspective

In virtue of his functions, the president of the Republic is empowered with full powers to negotiate international treaties and agreements and ratify them. The parliament is informed of such treaties and agreements following their conclusion. However, peace treaties and treaties or agreements relating to commerce and international organizations and those which commit state finances, modify provisions of laws already adopted by parliament or relates to the status of persons, can only be ratified after authorization by parliament. However, it is not permitted to cede or exchange part of the territory of Rwanda or to join the Rwandan part of another country without the consent of the people by referendum. The president of the republic and parliament shall be informed of all negotiations relating to treaties and international agreements which are not subject to ratification by the president of the republic.

It is also prohibited to make international agreement permitting foreign military bases on the national territory. It is prohibited to make international agreement permitting the transit or dumping of toxic waste and other hazardous materials capable endangering public health and environment.

Upon their publication in the official gazette, international treaties and agreements which have been conclusively adopted in accordance with the provisions of law, International conventions shall be more binding than organic laws and ordinary laws except in the case of non-compliance by one of parties.

However, as stipulated by the Vienna convention on the law of treaties, Rwandan constitution provides that in the event that the supreme court, upon request by competent organs (president of the republic, president and speaker of the chambers of parliament of one-fifth of members of the chamber of deputies or the senate) rules that an international treaty contains provisions which are inconsistent with the constitution, the authorization to ratify the treaty or agreement cannot be granted until the constitution is amended.

Custom as a source of law remains applicable as long as it has not been replaced by written laws, is consistent with the constitution, laws and regulations, and does not violate human rights, prejudice public order or offend public decency and morals.
Conclusion

Treaty and custom form distinct, interrelated, sources of international law. A norm deriving from one of these two sources may have an impact upon the content and interpretation of norms deriving from the other source. In principle, however, each retains its separate existence as a norm of treaty law or of customary law respectively.
In practice, the unending relationship between international custom and treaty is that a treaty rule is fleshed out by practice which in turn becomes evidence of a general practice accepted as law. A treaty may be declaratory of a custom, crystallize custom and may serve to generate a rule of customary law by subsequent State practice.
As it can be observed, customary international law is slow in its law making process and lack precision as it is based on a generality rather than universality of practice while treaties are both faster in the law making process and precise in their nature. Therefore, it is a fact that international custom and international convention, though different, remain intertwined in most of the cases.

References

International conventions

United Nations charter of 26th June 1945

Vienna Convention on the Law of Treaties 23rd May 1969

Laws

Rwandan constitution of 04/06/2003

Books

Alex Moseley,” Just War Theory," in The Internet Encyclopedia of Philosophy (accessed 27th January 2011); available at: http://www.utm.edu/research/iep/j/justwar.htm; Internet.

ICRC. (1998), to serve and to protect: Human rights and humanitarian law for police and security forces, Geneva.

James T.J., (1981), Just War Tradition and Restraint of War: A moral and historical Inquiry, Princeton university press, New Jersey

Prof. Starke J.G (2011), Available on Internet “www.suite101.com/content/international-law-and-australian-institutions-a272588 accessed on 26th January 2011

Rebecca M.M.W., (2002), International Law. Fourth edition, Sweet and Maxwell. London.

Articles

The Institute of International law, (1995), Problems Arising from the succession of Codification Conventions on a particular subject, session of lisbonne

Internet

http://www.en.wikipedia.org/wiki/sources_of_international_law, accessed on 27th January 2011

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[ 2 ]. Prof. Starke J.G (2011), Available on Internet “www.suite101.com/content/international-law-and-australian-institutions-a272588 accessed on 26th January 2011
[ 3 ]. Art. 38. 1b of the ICJ statute
[ 4 ]. ICRC. (1998), to serve and to protect: Human rights and humanitarian law for police and security forces, Geneva. P 38
[ 5 ]. Ibid.
[ 6 ]. Rebecca M.M.W., (2002), International Law. Fourth edition, Sweet and Maxwell. London P.9
[ 7 ]. Idem
[ 8 ]. Rebecca M.M.W. Op. cit. P 10
[ 9 ]. Ibidem
[ 10 ]. Art. 38 (1) b.
[ 11 ]. Ruzié D. (2006) Droit International public, 18e edition, Dalloz. Paris, P.54
[ 12 ]. Rebecca M.M. W. Op. Cit. P. 9
[ 13 ]. Art. 2. par. 1 (a) of the Vienna Convention on the law of treaties (1969)
[ 14 ]. Rebecca M.M.W. Op. Cit. P. 231
[ 15 ]. Art. 102 of the UN charter
[ 16 ]. Art. 46 of Vienna Convention on the Law of Treaties 1969
[ 17 ]. Rebecca M.M.W. Op. Cit. P.233
[ 18 ]. Art. 2 (c) Op. Cit
[ 19 ]. Rebecca M.M.W. Op. Cit. 233
[ 20 ]. Art. 9 Op. Cit.
[ 21 ]. From art. 11-16 Op. Cit.
[ 22 ]. Art. 26 Op. Cit.
[ 23 ]. Rebecca M.M.W. Op. Cit. P.239
[ 24 ]. Art. 31 Op. Cit.
[ 25 ]. Art. 34 Op. Cit.
[ 26 ]. Art. 38 Op. Cit.
[ 27 ]. Art 40 Op. Cit
[ 28 ]. Art 41 Op. Cit
[ 29 ]. Art. 46-53 Op. Cit.
[ 30 ]. Art. 54-61 Op.Cit.
[ 31 ]. Art. 69 (1,2) Op. Cit.
[ 32 ]. Art. 69 (3) Op. Cit
[ 33 ]. Rebecca M.M.W. P.250
[ 34 ]. http://www.en.wikipedia.org/wiki/sources_of_international_law consulted on 27th January 2011
[ 35 ]. James T.J., (1981), Just War Tradition and Restraint of War: A moral and historical Inquiry, Princeton university press, New Jersy. P. 4
[ 36 ]. Alex Moseley,"Just War Theory," in The Internet Encyclopedia of Philosophy (accessed 27th January 2011); available at: http://www.utm.edu/research/iep/j/justwar.htm; Internet.
[ 37 ]. Art. 2 of UN Charter
[ 38 ]. Art. 51 of UN Charter
[ 39 ]. http://www.en.wikipedia.org/wiki/sources_of_international_law consulted on 27th January 2011
[ 40 ]. Vienna Convention on Diplomatic Relations, 1961, and the Convention on the High Seas, 1958, are two examples for instances where customary rules were codified by treaties. The preamble of the Convention of the High Seas, 1958, states that it is “generally declaratory of established principle of international law.”
[ 41 ]. Meanwhile, the treaty assuring Belgium’s neutrality gave rise to a custom of accepting that country as neutral territory. In 1914, when Germany violated this custom, it angered the British politicians and public alike, prompting Britain to declare war on Germany.
[ 42 ]. Art. 31 of the Vienna Convention on the law of treaty 1969
[ 43 ]. Art 38 of ICJ statute
[ 44 ]. The Institute of International law (1995), Problems Arising from a Succession of Codification Conventions on a Particular Subject, session of lisbonne
[ 45 ]. http://chinesejil.oxfordjournals.org/content/9/1/81.full
[ 46 ]. Art.189 (a,b) of Rwandan constitution of 04/06/2003
[ 47 ]. Art. 189 (c,d) Op. Cit
[ 48 ]. Art. 191 Op. Cit
[ 49 ]. Art. 190 Op. Cit
[ 50 ]. Article 27 of the Vienna Convention on the law of treaties provides that, where a treaty conflicts with a state's municipal law (including the state's constitution), the state is still obliged to meet its obligations under the treaty.
[ 51 ]. Art 145 (4) of Rwandan constitution
[ 52 ]. Art. 192, Op. Cit.
[ 53 ]. Art. 201 (c) Op. Cit.