1

CHAPTER 2CHAPTER 2

THE SOURCES OF THE SOURCES OF

INTERNATIONAL LAWINTERNATIONAL LAW

PROFESSOR PROFESSOR

DR. ABDUL GHAFUR HAMIDDR. ABDUL GHAFUR HAMID

IntroductionIntroduction

• Every legal system has its own sources of

law.

• A rule of law must come from a particular

source.

• What type of law the international courts

and tribunals apply in deciding cases?

Formal sourcesFormal sources’’ and and ‘‘material sourcesmaterial sources’’

[Textbook pp. 22[Textbook pp. 22--23]23]

• The formal source is the source from which the

legal rules derive its legal validity or the

mechanism through which the law comes into

being. Its function is to create law (law-creating).

• The material source indicates where the legal

rules are located or the place – normally a

document of some kind – in which the substance

of the rule can be found. Its function is to identify

law (law-identifying).

Formal and material sources Formal and material sources [Cont.][Cont.]

• Only the formal source is the real source. The material source refers to some materials that may lead to a formal source.

• Under Art. 38 of the statute of the ICJ, there are three formal sources: treaty, custom and general principles of law. The rest are the material sources.

• Examples of the material source: a treaty, a resolution of the GA, a judicial decision, national legislation, an article of an eminent writer, etc.

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2. 1 ART. 38 OF THE STATUTE THE 2. 1 ART. 38 OF THE STATUTE THE

I.C.J.I.C.J. [pp.23[pp.23--24]24]

Article 38 of the Statute of the ICJ:

1.(a) International conventions, whether

general or particular, establishing rules

recognized by the contesting States;

(b) International custom, as evidence of a

general practice accepted as law;

(c) The general principles of law recognized by civilized nations;

(d) Subject to the provisions of Art. 59, judicial decisions and the teachings of the most highly qualified publicists

2. To decide a case ex aequo et bono if the parties agree thereto.

Art. 38 is generally regarded as an authoritative statement of the sources of international law.

• A question may be raised as to whether the enumeration of sources in Art. 38 is adequate in the modern context.

• Suggestions that there are other possible sources apart from those mentioned in Art. 38.

• But no such other possible source can claim the same authority in creating law as the three formal sources in Art. 38. And they are not supported by state practice.

• As far as the IC J is concerned, it is bound by its Statute.

2. 2 TREATIES2. 2 TREATIES[Textbook pp. 24[Textbook pp. 24--28]28]

• Art. 38(1)(a): the word ‘convention’ means a

treaty; it is an agreement made between two or

more States or other subjects of international

law.

• ‘Treaty’ is a generic term; the ‘Law of Treaties’.

• Terminology: treaty, convention, pact, protocol,

charter, covenant, accord, statute, exchange of

notes, and so on.

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The importance of treaties in The importance of treaties in

international lawinternational law

• Growing importance of treaties.

• More than 33,000 treaties - registered with the UN (See UNTS).

• International law has expanded enormously by virtue of a great number of treaties made by States.

• Customary international law derives from the practice of States. It is by nature slow in its law-making process. There is lack of precision. It is quite difficult to ascertain their exact contents.

• On the other hand, treaty-making process is relatively faster.

• States may enter into a treaty at any time when they feel that a new rule is required.

• Treaties are the only way by which international law can be made by a deliberate act of States.

• Since treaty law is a kind of written law (jus scriptum), it possesses the merit of considerable precision.

LawLaw--making treaties and treatymaking treaties and treaty--contractscontracts

• Some writers – argued: treaties should be

regarded as sources of international law only if

they are the so-called ‘law-making treaties’.

• A law-making treaty: one concluded by a

substantial number of States and stipulates new

general rules for future international conduct or

abolishes, modifies or codifies existing rules.

• The so-called treaty-contracts are treaties

between two or only a few States, dealing

with a special matter concerning these

States exclusively.

• According to this theory, the so-called

‘treaty-contracts’, are not a source of

international law but are merely legal

transactions.

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• It is difficult to accept this idea.

• The so-called treaty-contracts may, as between the parties thereto, constitute particular law.

• Moreover, even bilateral treaties may provide evidence of customary rules.

• The better view, therefore, is to regard all treaties as a source of law.

2.2.1 Binding force of treaties2.2.1 Binding force of treaties

• States have the capacity to enter into treaties.

• A treaty is based on consent. Such consent may

be expressed by (signature, ratification,

accession, etc.).

• Pacta sunt servanda. Article 26 of the VCLT:

• Every treaty in force is binding upon the parties

to it and must be performed by them in good

faith.

• A treaty – not binding on non-parties.

• Pacta tertiis nec nocent nec prosunt: A treaty may not impose obligations or confer rights on a third party

• Certain German Interests in Polish Upper Silesia case, 1926 (PCIJ): “a treaty only creates law as between the States which are parties to it’.

• Article 34 of the VCLT: “A treaty does not create either obligations or rights for a third State without its consent”.

2.2.2 Interaction between treaty law and 2.2.2 Interaction between treaty law and

customary law customary law [pp. 26[pp. 26--28]28]

• Treaty and custom interact and interrelate in an interesting way.

(a) Treaty as a material source of

customary law:

North Sea Continental Shelf cases [See p. 27 for the details]: the role of multilateral treaties as State practice and hence as a material sourceof CIL binding upon parties and non-parties alike.

• In the Court’s view, a treaty rule may relate to custom in one of three ways:

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(1) It may be declaratory of custom (that is, it may

codify (embody) a pre-existing rule of CIL);

(2) It may crystallize custom (that is, by means of

a very widespread and representative

participation in the treaty, including that of

States

whose interests are specially affected ); and

(3) It may serve to generate a rule of CIL in the

future by subsequent practice of States.

• When a treaty codifies existing CIL, the

obligations specified in the treaty may be binding

on all States, because:

(1) those States that are parties are bound by the

obligations in the normal way since they are

parties; and

(2) States that are not parties are also bound by

the obligations because they are rooted in CIL.

(b) Parallel existence of treaty rule and

customary rule: In the Nicaragua case, Nicaragua brought a claim

against the US alleging that the latter had used armed force and intervened in its affairs contrary to international law.

The US argued that the court had no jurisdiction because they had made a multilateral treaty reservation.

• Nicaragua claimed, however, that the Court had

jurisdiction because its claim was also based on

rules of customary international law.

• The Court held that the customary rules on the

use of force and intervention continued to bind

the parties in parallel with the obligations under

the UN Charter.

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2. 3 INTERNATIONAL CUSTOM2. 3 INTERNATIONAL CUSTOM

[pp. 29[pp. 29--40]40]

• The oldest and the original source.

• Article 38 (1)(b) refers to “international custom, as evidence of a general practice accepted as law”.

• This provision makes it clear that there are two essential elements of international custom:

(1) State practice; and

(2) acceptance as law or the so-called opinio

juris. [opinio juris sive necessitatis: Opinion as to law or necessity].

• This is reaffirmed by the ICJ in the famous North Sea Continental Shelf cases [See p. 27 for the details]

• In this case, Denmark and the Netherlands argued that the ‘equidistance principle’ in Article 6(2) of the 1958 Geneva Convention on the Continental Shelf applied because it stated or crystallized customary international law. (FRG was not a party to the Convention).

• The Court rejected their argument and ruled:

North Sea Continental Shelf cases, Judgment North Sea Continental Shelf cases, Judgment

[See, p. 29][See, p. 29]

• “[I]n order to achieve this result, two conditions must be fulfilled. Not only must the acts concerned amount to a settled practice, but they must also be such… as to be 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, i.e., the existence of a subjective element, is implicit in the very notion of the opinio juris sive necessitatis. The States concerned must therefore feel that they are conforming to what amounts to a legal obligation.

• Again, in the Continental Shelf (Libya v Malta)case, (1985) ICJ Rep. 29, the World Court stated that the ‘substance of customary international law must be looked for primarily in the actual practice and opinio juris of States’.

• This is the established doctrine, accepted by States, international tribunals and most writers alike.

• Hence, two elements of customary international law are: (1) State practice and (2) opinio juris.

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2. 3. 1 State Practice2. 3. 1 State Practice[p. 30][p. 30]

• The formation of a customary rule requires

a general and consistent State practice.

• Then what acts constitute State practice?

• Generally speaking, the actual words and

actions and omissions of States constitute

State practice.

• Even silence on the part of States is

relevant because passiveness and

inaction with respect to claims of other

States can produce a binding effect

creating legal obligations for the silent

State under the doctrine of ‘acquiescence’.

Where to look for evidence of State practiceWhere to look for evidence of State practice

[What are the material sources of custom?][What are the material sources of custom?]

(1) Treaties;

(2) Judicial decisions;

(3) National legislation;

(4)Diplomatic correspondence;

(5) Opinions of national legal advisors;

(6) Resolutions relating to legal questions of the

General Assembly

(7) Practice of international organizations.

• Evidence of customary law may also be

found in the writings of international

lawyers, and in judgments of national and

international tribunals, which are

mentioned as subsidiary means for the

determination of rules of law in Article

38(1)(d) of the Statute of the International

Court of Justice.

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2. 3. 1. 1 Generality of practice 2. 3. 1. 1 Generality of practice

[p. 31][p. 31]

• It refers to the number of States which have to

contribute towards the customary rule.

• Universality is not required.

• Common and widespread practice among a

significant number of States is required in order

for a ‘general custom’ (a rule of general

customary international law) to develop (as

opposed to a ‘local custom’ binding only a few

States).

• The available practice on the matter will have to

be so widespread that any inconsistent practice

will be marginal and without direct legal effect.

• If State practice is substantially divided and

conforms to two or more differing solutions on

one issue, it is not sufficiently widespread and

cannot amount to a general customary rule; of

course, a number of local, regional, or special

customs may arise.

(a) The practice of (a) The practice of ‘‘specially affectedspecially affected’’ StatesStates

[p. 31][p. 31]

• State practice must include the practice of those

States whose interests are ‘specially affected’ by

the subject matter of the rule (North Sea CS

case)

• For example, the practice of major maritime

powers will have more significance in the

formation of rules on the law of the sea than, for

example, that of a landlocked State.

((b) The effect of acquiescence in the formation b) The effect of acquiescence in the formation

of international customof international custom

• During the development of a customary rule, a State may react in three possible ways:

(i) by doing nothing (that is, complete silence or acquiescence);

(ii) by objecting to the practice from the outset (that is, the persistent objector); or

(iii) by objecting at a later date when the rule has already established as a custom (that is, the subsequent objector).

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• Where there has been a widespread and consistent State practice, then silence by others may be interpreted as ‘acquiescence’ in the development of a rule of CIL.

• All States (whether or not they have participated in the practice) are presumed to have assented to the rule unless they can demonstrate that they have the status of a persistent objector.

• Once a rule of general CIL has been established, the rule is binding upon all States(with the exception of a persistent objector State).

(c) The practice of dissenting States [p. 32](c) The practice of dissenting States [p. 32]

The Persistent objector [p. 33]The Persistent objector [p. 33]

• A State may contract out of a custom in

the process of formation.

• When a State object to a particular

practice carried on by other States or

adopts a contrary practice, it may not be

bound by any evolving customary law.

This is known as the concept of ‘persistent

objector’.

• A persistently objecting State is not bound by the eventual customary rule if the State fulfils two conditions.

• First, the objections must have been maintained from the early stages of the rule onwards, up to its formation, and beyond.

• Secondly, the objections must be maintained consistently. Evidence of objection must be clearand there is probably a presumption of acceptance, which is to be rebutted.

•

• The persistent objector rule appears to have been accepted by overwhelming majority of writers and in the practice of States.

• The authority that supports this rule is the Anglo-Norwegian Fisheries case (1951) ICJ Rep. 3.

• The ICJ made a finding that a coastline delimitation rule put forward by the UK was inapplicable as against Norway, as she has always opposed any attempt to apply it to the Norwegian coast.

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The subsequent objector The subsequent objector

• What is the effect of dissent by a State after a custom has been established?

• The general rule is that subsequent objection to an established rule of customary law cannot prevent that rule binding the State.

• However, subsequent objections or derivations may become so widespread that the previous rule is destroyed and replaced by a new rule, as with the extension of the territorial sea from 3 to 12 miles.

(d)(d) Local or regional custom Local or regional custom [p. 35][p. 35]

• There can be a local (or regional) customs amongst a group of States or just two States. The World Court recognized this in the Asylum case (Columbia v Peru) (1950) ICJ Rep. 266.

• “The Party which relies on a custom of this kind (i.e. Columbia) must prove that the rule invoked by it is in accordance with a constant and uniform usage practised by the States in question, and that this usage is the expression of a right appertaining to the State granting asylum and a duty incumbent on the territorial State.”

• In this case, the Court found against the existence of local custom because of lack of evidence. However, the possibility of local custom was confirmed in the Rights of Passage over Indian Territory case (Portugal v India) (1960) ICJ Rep. 6.

• “The Court sees no reason why long continued practice between two States accepted by them as regulating their relations should not form the basis of mutual rights and obligations between the two States.”

2. 3. 1. 2 2. 3. 1. 2 Consistency of practiceConsistency of practice[p. 36][p. 36]

• State practice must be reasonably consistent.

This criterion is satisfied if there is substantial,

rather than total or complete, consistency. The

ICJ held in the Nicaragua case that:

• “The Court does not consider that… the

corresponding practice must be in absolutely

rigorous conformity with the rule…The conduct

of States should, in general, be consistent with

such rules…”

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2. 3. 1. 3 2. 3. 1. 3 Duration of practiceDuration of practice[p. 37][p. 37]

• The duration of practice is a part of generality and consistency.

• A long practice is not necessary and rules relating to airspace and the CS have developed within a short period of time.

• In the North Sea Continental Shelf cases, the ICJ states: “the length of time needed will vary from subject to subject and that the passage of only a brief period of time is not necessarily a bar to the formation of customary law”

Can there be an Can there be an ‘‘instant customary international instant customary international

lawlaw’’ or or ‘‘dirittodiritto spontaneospontaneo’’? ?

• Proponents: Roberto Ago and Bin Cheng.

• This idea is to deny the significance of State practice and the relevance of time factor in the formation of CIL and to rely solely on opinio juris.

• However, it is not in accord with the consistent jurisprudence of the ICJ that State practice is an essential requirement.

• Thus, the possibility of instant custom has remained a matter of dispute.

2. 3. 2 2. 3. 2 OpinioOpinio jurisjuris sivesive necessitatisnecessitatis[pp. 37[pp. 37--39]39]

• The second element of an international custom is that the practice must be ‘accepted’ by States as ‘law’.

• It is necessary to examine not only what States do but also why they do it. There is a psychological element in the formation of customary law.

• State practice alone is not sufficient; it must be shown that it is accompanied by a conviction that it is binding upon them as law. (The conviction by States in the obligatory nature of the practice).

The requirement of The requirement of opinioopinio jurisjuris

• There must be some criteria by which we can

distinguish State practice amounting to law from

other kinds of State activity, such as acts of

comity or courtesy or friendship.

• In the Lotus case, The PCIJ held: “opinio juris

was an essential element in the formation of

customary international law.”

• This was reaffirmed in the North Sea Continental

Shelf cases and has been accepted ever since.

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Proof of Proof of opinioopinio jurisjuris

• (1) The opinio juris simply can be proved

by an express, or most often tacit,

acceptance of the practice as law by the

interested States. The express declaration

of a State that a given rule is obligatory (or

customary) indicates the clearest evidence

as to the State’s legal conviction. Express

acceptance is, however, rather rare.

• (2) From the judgment of the ICJ in the

Nicaragua case, it is clear that opinio juris

can be inferred from the actual behaviour

of States; it can be gathered from acts or

omissions of States.

• (3) “Protest” plays a very important role in ascertaining the element of ‘acceptance as law’. Absence of protests or objections against a practice (that is, acquiescence) tends to prove that States do not consider the practice as contrary to their interests and also, that they do not object to the formation of a customary rule. Toleration’ of a practice by other States, considering all relevant circumstances, justifies the presumption of its acceptance as law.

• (4) Casting an affirmative vote to a resolution of an IO or ratifying an international convention is also a clear commitment in the nature of opiniojuris. The Court stated in the Nicaragua case:

• “As regards the US in particular, the weight of an expression of opinio juris can similarly be attached to its support of the resolution of the Sixth Int. Conf. of American States condemning aggression … and ratification of the Montevideo Convention”

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2. 4 2. 4 GENERAL PRINCIPLES OF GENERAL PRINCIPLES OF

LAWLAW [pp. 40[pp. 40--41]41]

• ‘General principles of law’ are the legal

principles which are accepted in all or

most of the national systems of law, in so

far as they are applicable to relations of

States.

• The main objective: to fill in gaps in treaty

law and customary law and to meet the

possibility of a non liquet.

Examples of general principles of lawExamples of general principles of law

(1) The duty to provide ‘reparation’ in consequence of a wrongful act (ChorzowFactory case), which is accepted in most legal systems.

(2) Some of the general principles are based on ‘natural justice’ common to all legal systems such as the principles of good faith, estoppel or acquiescence, and proportionality.

(3) Some are based on legal logic or statutory interpretation, such as the principles of lexposterior derogat legi priori, and lex specialisderogat legi generali.

• (4) Some can be found in the field of

evidence, procedure and jurisdictional

questions. E.g., nemo judex in causa sua

(no man shall be judge in his own cause),

and res judicata .

2. 5 JUDICIAL DECISIONS AND 2. 5 JUDICIAL DECISIONS AND

WRITINGS OF JURISTSWRITINGS OF JURISTS[pp. 41[pp. 41--42]42]

• Article 38(1)(d) of the Statute of the Court

directs the Court to apply “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”.

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2. 5. 1 Judicial decisions2. 5. 1 Judicial decisions

• Article 59 of the Statute says: “The decision of

the Court has no binding force except between

the parties and in respect of that particular

case”.

• It means that in international law there is no

concept of stare decisis, as known in common

law system.

• In theory, therefore, judicial decisions do not

make law but are declaratory of pre-existing law.

• Although international courts are, in principle, not obliged to follow previous decisions, in practice they almost always take previous decisions into account.

• The ICJ always strive to maintain ‘judicial consistency’, referring to previous decisions.

• Therefore, whatever the theory, the Court in practice is involved in the process of law-creation. First, the decision of the Court has created law for the parties. Secondly, a decision of the Court may have a profound impact on customary law.

• Since Article 38(1)(d) is not limited to decisions

of the World Court, there is no reason why

decisions of other judicial bodies should not be

regarded as sources of international law.

• Even decisions of domestic courts, if they deal

with matters of international law, may provide

important evidence as to the practice of States

and a material source from which a rule of

customary international law can emerge.

2. 5. 2 Writings of publicists2. 5. 2 Writings of publicists

• The writings of the most highly qualified publicists are also to be regarded as a ‘subsidiary means for the determination of rules of law’.

• However, they are a material or evidential source only.

• Must be careful about the integrity and political background of the writer.

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2. 6 OTHER POSSIBLE SOURCES2. 6 OTHER POSSIBLE SOURCES

• Having examined the sources mentioned

in the Statute of the Court, our concern

now is to consider whether there are any

other possible sources, which have been

omitted in the list.

2. 6. 1 General Assembly Resolutions2. 6. 1 General Assembly Resolutions

• As a rule, General Assembly resolutions are not binding on member states.

• Nevertheless, when they are concerned with substantive questions of IL, there may be an interaction between these and CIL.

• Like treaties, GA resolutions may be declaratory of existing CIL. They may also crystallize State practice so that a new customary rule is created.

• In other words, they may be evidence of State practice and a material source of customary international law.

• In the Legality of the Threat and Use of Nuclear

Weapons case (1996) ICJ Rep. 66, the ICJ

stated:

• “The GA resolutions, even if they are not

binding, may sometimes have normative value.

They can …provide evidence important for the

emergence of an opinio juris…. a series of

resolutions may show the gradual evolution of

the opinio juris required for the establishment of

a customary rule.”

2. 6. 2 Equity2. 6. 2 Equity

• Equity is used here in the sense of considerations of ‘fairness’, and ‘reasonableness’.

• In Diversion of Water from the Meuse Case, the Netherlands claimed that Belgium had infringed a treaty obligation by building canals that altered the flow of water in the River Meuse. Belgium argued that Netherlands had lost the right to bring the claim because of similar earlier conduct by itself.

• In other words, Belgium relied on the principle of estoppel by conduct.

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Diversion of Water from the Diversion of Water from the MeuseMeuse CaseCase

• Judge Hudson: “What are widely known as principles of equity have long been considered to constitute a part of international law, and as such they often been applied by international tribunals ….The Court has not been expressly authorised by its Statue to apply equity as distinguished from law … Article 38 of the Statute expressly directs the application of “general principles of law recognised by civilisednations”, and in more than one nation principles of equity have an established place in the legal system.”

References to References to ‘‘equityequity’’ can be found very often in can be found very often in

the judgments of the World Court.the judgments of the World Court.

• Examples include the River Meuse case itself (application of equitable principle of estoppel), the Temple of Preah Vihear case (1962) ICJ Rep. 6. (application of acquiescence/and also estoppel).

• In the North Sea Continental Shelf cases: the formulation of equitable principles concerning the delimitation of continental shelf.

• In the Gulf of Maine case. the ICJ stated that the concepts of acquiescence and estoppel in international law “follow from the fundamental principles of good faith and equity”.

2. 6. 3 Soft Law2. 6. 3 Soft Law

• In recent years a new idea has crystallized in the international community, which has: come to be known as ‘soft law’ (as opposed to ‘hard law’, which makes up international law proper).

• ‘Soft law’ can be defined as a body of guiding principles, standards, rules of conduct, or declarations of policy, which are not strictly binding norms of law.

• Some say that there exists a considerable “grey area” of “soft law” between the white space of “law” and the black territory of “non-law”.

• Soft law can be found in treaties not yet in force, in resolutions or declarations of international organizations, or in final acts of international conferences.

• It chiefly relates to human rights, international economic relations, and protection of the environment.

• Examples of soft law instruments: the Helsinki Final Act 1975, the Bonn Declaration on International Terrorism 1978, and the Rio Declaration on the Environment and Development 1992.

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2. 7 THE HIERARCHY OF THE 2. 7 THE HIERARCHY OF THE

SOURCESSOURCES [pp. 47[pp. 47--50]50]

• There is no indication in Article 38 of the Statute of the priority or hierarchy of the sources of international law.

• Apart from a reference to ‘subsidiary means’ in Article 38(1)(d), we do not know the order in which the sources of law are to be applied.

• When drafting the original text of Article 38, words of priority were included: “the sources listed should be considered by the Court in the undermentioned order (i.e., the order (a) to (d) in which they now appear)”; but ultimately they were deleted.

• Indeed, there is no difficulty if the rules

derived from the various sources are

complementary.

• However, in cases of conflict it is vital to

determine which source shall prevail.

(1) (1) Jus Jus cogenscogens: the highest in the hierarchy: the highest in the hierarchy

• A rule of jus cogens is a peremptory norm of general international law: “a norm accepted and recognized by the international community of States as a whole as a norm from which no derogation is permitted (Art. 53 of VCLT).

• As States cannot derogate from rules of jus cogens through treaties or customary rules, the treaty or customary rules contrary to them are null and void.

• Therefore, rules having the character of jus cogens are the highest in the hierarchy of the sources of international law.

(2) A treaty binding on the parties to the (2) A treaty binding on the parties to the

disputedispute

• If there is a treaty or convention, which is relevant to the subject matter of the dispute, and to which both parties to the dispute are parties, that treaty or convention will definitely be the law for the Court to determine the dispute.

• This is due to the two factors. First, a treaty is law for the parties to it. Secondly, it will normally be the case that a treaty is lex specialis, and as such prevails over any inconsistent rules of customary law

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• Again, in practice, Even though there is a treaty binding on the parties, there may be quite a number of legal issues involved in the dispute. The treaty cannot have solutions to all of them.

• The Court, unavoidably, has to apply customary law to deal with issues in respect of which there are no answers in the treaty.

• The Court will need to apply customary law to interpret the provisions of the treaty.

• Therefore, the Court in most cases apply both treaty law and customary law simultaneously.

Treaty versus customTreaty versus custom

• Treaty and custom, the two major sources, usually are quite complementary.

• A treaty may codify custom or may lead to the development of new customary law.

• On the other hand, States may abrogate a customary rule by concluding a treaty; the latter may again be modified by new customary law.

• Therefore, treaty law and customary law are generally of equal authority and of equal status (with the exception of the principle of jus cogens).

• In any case, in case of conflict, which law shall prevail? There are some guiding principles in this respect:

(1) lex posterior derogat legi priori (a later law repeals an earlier law).

(2) lex specialis derogat legi generalis (A special law prevails over a general law).

(3) Lex posterior generalis non derogat legi priori specialis (a later law, general in nature, does not repeal an earlier law which is more special in nature).

Inconsistent treatiesInconsistent treaties

• If there are successive treaties relating to the same subject matter, which treaty shall prevail?

• The answer can be found in Article 30 of VCLT, which is subject to Article 103 of the UN Charter.

• The essence of Article 30 is that ‘when all the parties to the earlier treaty are parties also to the later treaty, then the general rule of lex posterior derogat legi priori applies and the later treaty shall prevail over the earlier treaty’.

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• Article 103 of the Charter reads: “ In the event of a conflict between the obligations of the Members of the United Nations under the present Charter and their obligations under any other international agreements, their obligations under the present charter shall prevail”.

• This article is known as ‘clause paramount’ and it clearly acknowledges the supremacy of the UN Charter over any other treaties. See the Lockerbie case (Provisional Measures) (1992) ICJ Rep. 3, 114. [Textbook pp. 166, 456]

(3) Customary international law(3) Customary international law

• If there is no treaty binding on the two

parties to a dispute, or if one of the parties

to the dispute is not a party to the treaty,

then the Court has to rely exclusively on

customary international law for the

determination of the dispute.

(4) General Principles of Law and Other (4) General Principles of Law and Other

sourcessources

• Since the main function of general principles of law is to fill gaps in treaty law and customary law, it would appear that treaties and custom prevail over general principles of law in the event of conflict.

• Judicial decisions and learned writers are described in Article 38(1)(d) as ‘subsidiary means’ which suggests that they are subordinate to the other three sources listed: treaties, custom and general principles of law.