Sources of Law

Question 1

What are the sources of international law (that this Court is bound to apply)?

Answer 1

The sources of international law are set out in Art.38(1)(a)-(d) of this Court’s Statute and are, in order:

(a) treaties
(b) customary international law
(c) general principles of law, and
(d) Subject to the provisions of Art 59, 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

Question 2

Do any legal obligations arise from legal sources outside of Art. 38(1) ICJ Statute?

Answer 2

YES: Pursuant to paragraph 46 of this Court’s Nuclear Tests judgment, international obligations arising from unilateral declarations do not, for example, fall neatly within any of the three primary sources.

Question 3

What is the definition of a treaty?

Answer 3

Pursuant to Art. 2(1)(a) VCLT, a ‘treaty’ is (i) an international agreement (ii) concluded between States in (iii) written form and (iv) governed by international law.

Question 4

What is the ‘pacta sunt servanda’ principle?

Answer 4

Pursuant to Art. 26 VCLT, ‘pacta sunt servanda’ is the principle that a treaty is binding upon the States parties to it and must be performed by them in good faith.

Question 5

In general, are treaties retroactive in application?

Answer 5

NO: Pursuant to Art 28 VCLT, treaties are not binding before their entries into force unless a different intention appears from the treaty or is otherwise established.

Question 6

When did the VCLT enter into force? And when was it concluded?

Answer 6

The VCLT entered into force on 27 January 1980. The VCLT was concluded on 23 May 1969.

Question 7

What is the force of a treaty that a State has signed by not yet ratified?

Answer 7

Pursuant to Art. 18(a) VCLT, if a State has signed but not yet ratified a treaty, that State is obligated to refrain from acts that would defeat the object and purpose of the treaty.

Question 8

What is the force of a treaty that a State has ratified but that has not yet entered into force?

Answer 8

Pursuant to Art. 18(b) VCLT, if a State has ratified a treaty but the treaty has not yet entered into force, the State is obligated to refrain from acts that would defeat the object and purpose of the treaty.

Question 9

What does ‘defeat’ mean in Art. 18(a)-(b)?

Answer 9

Pursuant to the travaux of the VCLT, ‘defeat’ means to render the entry into force of the treaty “meaningless”

Question 10

What is the ‘object and purpose’ under Art. 18(a)-(b) and how do we find this?

Answer 10

The object and purpose of a treaty is a broad definition of its overall goals and spirit. It may be found by reading the treaty as a whole, including its title and preamble, as the ICJ did in paragraphs 57 and 91 in its preliminary objections judgment in the Certain Iranian Assets Case (Iran v USA) [2019]

Question 11

Are the ‘object and purpose’ different things?

Answer 11

No, the object and purpose are usually considered to be a unitary concept, and were treated as such by the ICJ in paragraphs 57 and 91 in its preliminary objections judgment in the Certain Iranian Assets Case (Iran v USA) [2019]

Question 12

Can a third State be bound by a provision of a treaty?

Answer 12

NO: Pursuant to Art. 34 VCLT, a treaty creates neither obligations nor rights for a third State without its consent.

(If elaboration needed: – However, pursuant to Art. 35 of the same Treaty, an obligation may arise for a third State if the parties to the treaty intend the provision to have that effect and if the third State expressly accepts the obligation in writing).

Question 13

What does “concluded” mean under Art. 4 of the VCLT?

Answer 13

There is no fixed definition of “concluded” under Art. 4 VCLT as it would not be appropriate for the purposes of treaty-creation. The process leading to “concluded” is best described as comprising three main stages – negotiation, drafting, and adoption.

Question 14

What is the relationship between a treaty and jus cogens norms?

Answer 14

A treaty cannot conflict with a peremptory norm of international law.

Pursuant to Art. 53 VCLT, a treaty is void, if, at the time of its conclusion, it conflicts with a jus cogens/peremptory norm of international law.

Pursuant to Art. 64 VCLT, if a new jus cogens/peremptory norm of international law emerges, any treaty that conflicts with that norm is void and terminates.

Question 15

What is the general rule of treaty interpretation?

Answer 15

Pursuant to Art. 31(1) VCLT, a treaty shall be interpreted in good faith in accordance with ordinary meaning to be given to its terms in their context, and in light of its object and purpose.

Question 16

Is the general rule of treaty interpretation representative of CIL?

Answer 16

YES: as confirmed by this Court at [48] of their Guinea-Bissau/Senegal judgment.

More recently, YES: as confirmed by this Court at [61] of its 2020 Immunities and Criminal Proceedings (Equatorial Guinea/France) judgment.

Question 17

How can travaux préparatoires be relevant to treaty interpretation?

Answer 17

Pursuant to Art. 32 VCLT, recourse to supplementary means of interpretation, including travaux, may be made in three circumstances:

(1) to confirm the meaning resulting from applying Art. 31 (i.e., the general rule of treaty interpretation); or

to determine the meaning if the result of applying Art. 31 either:

(2) leaves the meaning ambiguous or obscure; or
(3) leads to a result that is manifestly absurd or unreasonable.

Question 18

Is the VCLT retroactive in its application?

Answer 18

NO: Pursuant to Art. 4 VCLT, the VCLT is not retroactive and applies only to treaties concluded after the entry into force of the VCLT between the States parties to the treaty in question.

Question 19

If a State is bound by two conflicting treaties, which obligation prevails?

Answer 19

Pursuant to the principle of lex posterior, the latter treaty shall prevail.

Question 20

What is customary international law? What are the requirements of customary international law?

Answer 20

CIL is a source of law pursuant to Art. 38(1)(b) of this Court’s Statute. Pursuant to paras. 73-77 of this Court’s North Sea Continental Shelf Judgment, CIL consists of two elements:

(1) widespread and consistent State practice; and
(2) a belief amongst States that this practice is rendered obligatory by a rule of law requiring it (i.e., opinio juris)

Question 21

What is opinio juris? How can it be evidenced?

Answer 21

Pursuant to para. 77 of this Court’s North Sea Continental Shelf Judgment, opinio juris is one of two elements of CIL. It is the psychological element of belief amongst States that a certain practice is required by law.

It can be evidenced, for example, by the statements of governments (including, for example, in United Nations debates); the actions of governments in their relations with other States; and the application of international legal rules by domestic courts.

[188] Nicaragua: General Assembly resolutions.

Question 22

What is State practice? How can it be evidenced?

Answer 22

Pursuant to paras. 73-77 of this Court’s North Sea Continental Shelf judgment, State practice is one of two elements of CIL. It must be widespread and representative and must include the practice of specially affected States.

It is evidenced by the conduct of States.

Question 23

What is State practice? How can it be evidenced?

Answer 23

Pursuant to paras. 73-77 of this Court’s North Sea Continental Shelf judgment, State practice is one of two elements of CIL. It must be widespread and representative and must include the practice of specially affected States.

It is evidenced by the conduct of States.

Question 24

Does the State practice (for CIL) need to be universal (i.e., no derogations)?

Answer 24

NO: Pursuant to para. 186 of this Court’s Nicaragua Judgment, the State practice in question does not need to be universal or perfect – in general, all that is required is that the practice of States is consistent with the rule in question.

Question 25

In general, is State practice inconsistent with a given rule evidence that that rule does not exist?

Answer 25

NO: Pursuant to para. 186 of this Court’s Nicaragua Judgment, if the State practice is, in general, consistent with the rule in question, any examples of inconsistent practice should be treated as breaches of the rule, not as evidence that the rule does not exist.

Question 26

Has this Court ever restated its North Sea Continental Shelf dictum?

Answer 26

YES: for example, in its 2012 Jurisdictional Immunities Judgment at para. 55, this Court quoted, verbatim, its statements in North Sea Continental Shelf.

More recent: YES, for example at [149] of its 2019 Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 Advisory Opinion.

Question 27

Can actions ex gratia be evidence of CIL?

Answer 27

NO: Pursuant to para. 77 of this Court’s North Sea Continental Shelf Judgment, actions ex gratia cannot be evidence of CIL as they lack the belief that the practice in question is obligatory.

Question 28

Can a provision of a treaty become CIL? If so, what is required for a norm of a treaty to become CIL?

Answer 28

YES: as confirmed by this Court in its North Sea Continental Shelf and Nicaragua judgments, a treaty provision may become CIL if both State practice and opinio juris can be established.

However, as stated in para. 76 of the North Sea Judgment, evidence of opinio juris in this context must show that the States acting in accordance with the provision would have done so anyway and not just in fulfilment of their obligations under the treaty.

Question 29

Is there an example of a treaty that has been widely ratified by States but is not, as yet, considered to have crystallised in CIL?

Answer 29

YES: the UN Convention on the Rights of the Child is considered not to reflect CIL despite its 196 State parties.

Question 30

Consent of how many States is required for a norm to reach the level of customary international law?

Answer 30

Whilst there is no specific figure, the Court confirmed, at p. 39 of its Rights of Passage over Indian Territory judgment, that a rule of local CIL could be established by only 2 States.

Question 31

What is a ‘persistent objector’?

Answer 31

As outlined by this Court at p. 125 of its Anglo-Norwegian Fisheries Judgment, a persistent objector is a State that refuses to be bound by CIL during the time of its crystallisation.

Question 32

What is regional or local CIL?

Answer 32

Regional CIL may arise pursuant to the practices of States within a particular region or locale. In the Asylum case, the ICJ recognised that the scope of Art. 38 of its Statute encompassed bi-lateral and regional international customary norms.

Question 33

What are obligations erga omnes?

Answer 33

Pursuant to paragraph 33-34 of this Court’s Barcelona Traction Judgment, obligations erga omnes are those that are owed by States to the international community as a whole.

Question 34

What are obligations erga omnes partes?

Answer 34

Pursuant to paras. 68-9 of this Court’s Belgium/Senegal Judgment, obligations erga omnes partes are, in general, those owed by a State to all other State parties of a treaty.*

(*though, these obligations may also be owed to a select group of States in CIL.)

Question 35

What are jus cogens or peremptory norms of international law?

Answer 35

These are the norms, accepted by the international community as a whole, from which no derogation is permitted pursuant to Art. 53 VCLT.

Question 36

What are general principles of law?

Answer 36

A source of international law pursuant to Art. 38(1)(c) of this Court’s Statute.

Question 37

How do we establish or evidence general principles?

Answer 37

General principles may be evidenced by the provision of the rule in question in the internal constitutions, legislation and case law of States.

Question 38

What is a ‘civilised nation’?

Answer 38

The term “civilised nation” is now taken to mean all nations, except nations that evidence clear disregard for protection of fundamental human rights or conduct themselves in ways otherwise unacceptable to the international community.

Question 39

What is non liquet?

Answer 39

The term ‘non liquet’ means that there is no clear, applicable law. In its Nuclear Weapons Advisory Opinion, this Court implicitly found non liquet in rules on the use of nuclear weapons.

Question 40

What are the forms of State jurisdiction?

Answer 40

Territorial jurisdiction, effects doctrine, nationality, protective principle, universal jurisdiction, etc…

Question 41

Territorial jurisdiction principle.

Answer 41

A State has jurisdiction over an act committed within its territory.

Question 42

What is the ‘Effects Doctrine’?

Answer 42

The doctrine that a State may assert jurisdiction over an act committed abroad but having effects inside its territorial jurisdiction.

Question 43

Nationality (personality) principle.

Answer 43

The principle that a State may exercise jurisdiction over its own nationals and their conduct, even when they are outside of its territory.

Question 44

Protective Principle (Passive Personality).

Answer 44

The principle that allows States, in limited circumstances, to assert jurisdiction to try a foreign national for offenses committed abroad but affecting its own nationals.

Question 45

Principle of universal jurisdiction.

Answer 45

This principle allows States to assert jurisdiction in cases where the alleged crime may be prosecuted by all States (e.g. war crimes, crimes against the peace, crimes against humanity, slavery, and piracy).

Universal jurisdiction was exercised by State parties in the Eichmann, Pinochet and Arrest Warrant cases.

Question 46

Is there a hierarchy between the sources under Art. 38(1)?

Answer 46

YES: pursuant to Art. 38(1) of this Court’s Statute, paragraph (d) is a subsidiary means for the determination of primary sources found in paragraphs (a)-(c). However, there is no hierarchy between paragraphs (a)-(c).

Question 47

What is the weight of the sources found in Art. 38(1)(d)?

Answer 47

Art. 38(1)(d) is a subsidiary means for the determination of rules of law originating from the sources found in paragraphs (a)-(c).

Question 48

Is the ICJ bound by its prior decisions?

Answer 48

NO: pursuant to Art. 59 of this Court’s Statute, only the parties to a case are bound by the Court’s decision.

However, as confirmed in para. 53 of its Preliminary Objections Judgment in the Croatian Genocide Case (Croatia v Serbia), this Court will only depart from previous cases when there are ‘very particular reasons’ for doing so.

Question 49

What is the legal force of the judgments of the Permanent Court of International Justice?

Answer 49

Judgments of the PCIJ are judicial decisions within Art. 38(1)(d) of this Court’s Statute and may, therefore, be used as a subsidiary means to evidence a primary source of law.

Question 50

If a State has conflicting obligations under two treaties (or under a treaty and customary international law), which obligation prevails?

Answer 50

Pursuant to para. 274 of the Nicaragua case, (in general), treaty obligations prevail over CIL as lex specialis. (NB: court was not addressing the issue of when a treaty conflicts with a CIL norm).

Between two treaties, the latter one will prevail pursuant to the maxim lex posterior derogate lex priori, as codified in Article 30 VCLT.

Question 51

Which party bears the burden of proof before the ICJ? Does the doctrine of affirmative defence apply in international law?

Answer 51

The party bringing the claim bears the burden of proof pursuant to the onus probandi principle as stated in paragraph 54 of the Merits judgment in the Diallo case.

(But see the paragraphs immediately after for instances where the burden of proof may be reversed).

Question 52

What is the standard of proof required by international law?

Answer 52

Generally, it is one of balance of probabilities. For instance, this standard was used in Land, Island and Maritime Frontier Dispute (El Salvador/Honduras) at para. 248.

Question 53

In what circumstances is recourse to circumstantial evidence permitted?

Answer 53

As confirmed in p. 18 of the Corfu Channel Case, recourse to circumstantial evidence must leave no room for reasonable doubt. It may be permitted when:

(1) the direct evidence is under the exclusive control of the opposing party; and
(2) the circumstantial evidence does not contradict any available direct evidence or accepted facts.

Question 54

What is the legal force of resolutions of the UN General Assembly and the UN Security Council? How does the ICJ apply these documents?

Answer 54

Resolutions of the UNGA and UNSC are treaty law pursuant to Art. 38(1)(a) of this Court’s Statute and may, therefore, be applied as a primary source of law.

Question 55

Invalidity of treaties – Art. 46 VCLT

Answer 55

(Violation of internal law)

A State may only invoke a violation of its internal law regarding its competence to conclude treaties as invalidating its consent if

(i) the violation was manifest and
(ii) the rule of internal law is of fundamental importance.

Question 56

Invalidity of treaties – Art. 47 VCLT

Answer 56

(Representative exceeds its functions)

If the restriction on the authority of a representative to express the consent of a State to be bound by a particular treaty has been notified to the other negotiating States prior to his expressing such consent and is not observed.

Question 57

Invalidity of treaties – Art. 48 VCLT

Answer 57

(Error)

An error in a treaty may be invoked by a State to invalidate it if

(i) it relates to a fact or situation which was assumed by the State to exist when the treaty was concluded and
(ii) it formed an essential basis of the State’s consent.

Question 58

Invalidity of treaties – Art. 49 VCLT

Answer 58

(Fraud)

Fraud may invalidate a treaty if it induced a State to conclude that treaty.

Question 59

Invalidity of treaties – Art. 50 VCLT

Answer 59

(Corruption)

If the expression of a State’s consent to be bound by a treaty has been procured through the corruption of its representative directly or indirectly by another negotiating State, the State may invoke such corruption as invalidating its consent to be bound by treaty.

Question 60

Invalidity of treaties – Art. 51 VCLT

Answer 60

(Coercion)

Consent procured by coercion of a State’s representative has no legal effect.

Question 61

Invalidity of treaties – Art. 52 VCLT

Answer 61

(Use of force)

Threat or use of force to procure the conclusion of a treaty will render the treaty void.

Question 62

Invalidity of treaties – Art. 53 VCLT

Answer 62

(Conflict with jus cogens)

A treaty is void if, at the time of its conclusion, it conflicts with a peremptory norm of international law.

Question 63

Invalidity of treaties – Art. 62 VCLT

Answer 63

(Change of circumstances)

An unforeseen fundamental change of circumstances may be invoked as a ground for terminating a treaty if

(i) the circumstances constituted an essential basis of the consent of the parties and
(ii) the change radically transforms the extent of obligations under the treaty.

Question 64

What is ‘estoppel’–and, is it considered to be a general principle?

Answer 64

Estoppel protects the legitimate expectations of States induced by conduct of another State. Estoppel prevents a representing party from successfully adopting different or subsequent statements on the same issue without regard to their truth and accuracy.

The doctrine was first mentioned in the Barcelona Traction (Case Concerning Barcelona Traction, Light, and Power Company Judgment on 24 July 1964) and extensively analysed in the Temple of Preah Vihear Judgment of 15 June 1962, where it is recognised as a general principle in Judge Alfaro’s separate opinion, para. 43.

Question 65

What is ‘acquiescence’–and is it considered to be a general principle?

Answer 65

“Acquiescence” denotes unilateral consent via the silence or inaction of a State in circumstances where a response expressing disagreement or objection towards another State’s conduct would be called for. It is often entangled with “estoppel”.

It is considered a general principle, evidenced in the separate opinion of Judge Fouad Ammoun in the North Sea Continental Shelf Cases (Germany/Denmark and Germany/Netherlands) 20 Feb 1969 Judgment.

Question 66

What is ‘equity’–and, is it considered to be a general principle?

Answer 66

Whilst equity continues to exist, there is largely no definite notion of equity as a general principle, distinct from estoppel and acquiescence. Judge André Gros makes a remark of similar effect in his dissenting opinion in Gulf of Maine (Delimitation of the Maritime Boundary in the Gulf of Maine Area, Canada/USA) Judgment on 12 October 1984, expressing doubt towards the notion of equity in international law measured by “the judge’s eye”.