Validity of Treaties, and Jus Cogens

Note what article 45 leaves out. It does not mention articles 51, 52 and 53. A State cannot acquiesce its way into validating a treaty procured by coercion or conflicting with jus cogens, because those defects are not for the injured State alone to waive.

The grounds that make consent voidable

These five are invoked by the injured State, are subject to article 45, and are capable of severance under article 44(3).

Article 46, violation of internal law on competence

A State may not invoke the fact that its consent was expressed in violation of a provision of its internal law regarding competence to conclude treaties as invalidating that consent unless the violation was manifest and concerned a rule of its internal law of fundamental importance.

Article 46(2) defines manifest: a violation is manifest if it would be objectively evident to any State conducting itself in the matter in accordance with normal practice and in good faith.

Both conditions must be met, and the test of manifestness is objective and set from the standpoint of the other States. The reason for the strictness is stated in article 27: States cannot be required to audit each other's constitutions.

Article 47, specific restrictions on authority

Where a representative's authority has been made subject to a specific restriction, his failure to observe it may not be invoked as invalidating the consent unless the restriction was notified to the other negotiating States before he expressed consent.

This is not a defect in the treaty at all; it is a rule about who bears the risk of a private instruction.

Article 48, error

A State may invoke an error as invalidating its consent if the error relates to a fact or situation which was assumed by that State to exist at the time the treaty was concluded and formed an essential basis of its consent.

Article 48(2), the two bars. The paragraph does not apply if the State contributed by its own conduct to the error, or if the circumstances were such as to put that State on notice of a possible error.

Article 48(3). An error relating only to the wording does not affect validity, and article 79 on correction of errors applies instead.

Error of fact, then, and not error of law, and only where the State was not itself at fault. In practice the plea has almost always failed, most famously in boundary cases where a State signed a map it had every opportunity to check.

Article 49, fraud

If a State has been induced to conclude a treaty by the fraudulent conduct of another negotiating State, it may invoke the fraud as invalidating its consent.

Article 50, corruption of a representative

If consent has been procured through the corruption of the State's representative, directly or indirectly, by another negotiating State, the State may invoke the corruption.

The corrupting State must be a negotiating State, so bribery by a private company or a stranger is not within the article.

The grounds that make the treaty void

These three operate absolutely: no severance under article 44(5), no acquiescence under article 45.

Article 51, coercion of a representative

The expression of consent procured by the coercion of a representative through acts or threats directed against him shall be without any legal effect.

The coercion is aimed at the person: threats to his family, his liberty, his reputation.

Article 52, coercion of a State

A treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations.

The historic importance is that this reversed the old law. For centuries the peace treaty imposed by the victor was valid, and the validity of coerced treaties was the ordinary way conquest was made lawful, as [Acquisition of State Territory] records. Article 52 makes the coerced treaty void.

What counts as force. The article says the threat or use of force in violation of the principles embodied in the Charter, which points to article 2(4) and therefore to armed force. Whether severe economic or political pressure is within article 52 was contested at the conference and left unresolved; a Declaration adopted with the Convention condemned such pressure without putting it in the article. The correct answer states that the point is unsettled and says which way the text points.

Article 53, jus cogens

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

The definition, which must be quoted accurately. For the purposes of the Convention, a peremptory norm of general international law is a norm accepted and recognised by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.

Three elements. Acceptance and recognition by the international community of States as a whole; non-derogability; and modifiability only by a later norm of the same character.

What the Convention does not do. It gives no list. The examples generally accepted, and which may be offered in an answer with the caveat that the Convention names none, are the prohibition of aggression, of genocide, of slavery and the slave trade, of torture, of apartheid and racial discrimination, of crimes against humanity, and the right of self-determination.

Article 64, supervening jus cogens. If a new peremptory norm emerges, any existing treaty which is in conflict with that norm becomes void and terminates. Note the difference from article 53: article 53 voids the treaty from the beginning, article 64 terminates it from the emergence of the norm.

Jus cogens against custom and erga omnes. An ordinary customary rule binds unless displaced by agreement; a peremptory norm cannot be displaced by agreement at all. Obligations erga omnes, as [State Responsibility] explains, are owed to the international community as a whole so that every State has an interest in compliance; that concerns who may complain, while jus cogens concerns what may be agreed. Most peremptory norms generate erga omnes obligations, but the two ideas answer different questions.

Procedure: articles 65 to 68

A ground is not self-executing. The Convention makes a State prove it before acting.

Article 65(1). A party invoking a defect in consent or a ground for impeaching validity, terminating, withdrawing or suspending must notify the other parties, indicating the measure proposed and the reasons.

Article 65(2). If, after not less than three months from receipt, except in cases of special urgency, no party has objected, the notifying party may carry out the measure through the instrument required by article 67.

Article 65(3). If objection is raised, the parties shall seek a solution through the means indicated in Article 33 of the Charter, that is negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, resort to regional agencies, or other peaceful means of their choice.

Article 66, the compulsory element. If no solution is reached within twelve months after the objection, then for a dispute concerning article 53 or 64, that is jus cogens, any party may submit it to the International Court of Justice by written application unless the parties agree on arbitration; for any other article in Part V, a party may set in motion the conciliation procedure in the Annex by request to the Secretary-General.

That is a rare thing in the Convention: compulsory jurisdiction, confined to jus cogens. It was the price of including articles 53 and 64 at all, and several States that voted against the Convention did so over this pairing.

Article 67. The notification must be in writing, and the act itself carried out through an instrument communicated to the other parties, whose signatory may be asked for full powers if not the Head of State, Head of Government or Foreign Minister.

Article 68. A notification or instrument may be revoked at any time before it takes effect.

Consequences: articles 69 and 71

Article 69(1). A treaty whose invalidity is established is void, and the provisions of a void treaty have no legal force.

Article 69(2). Where acts have nevertheless been performed in reliance on it, (a) each party may require any other to establish as far as possible the position that would have existed had the acts not been performed, and (b) acts performed in good faith before the invalidity was invoked are not rendered unlawful by reason only of the invalidity.

Article 69(3), the guilty party's disability. In cases of fraud, corruption or coercion, paragraph 2 does not apply with respect to the party to which the fraud, corruption or coercion is imputable. The wrongdoer gets no good-faith protection.

Article 71(1), jus cogens under article 53. The parties shall eliminate as far as possible the consequences of any act performed in reliance on the conflicting provision, and bring their mutual relations into conformity with the peremptory norm.

Article 71(2), jus cogens under article 64. Termination releases the parties from further performance and does not affect rights, obligations or situations created by execution before termination, provided that they may thereafter be maintained only to the extent that their maintenance is not in itself in conflict with the new peremptory norm.

A worked example

State AA's Foreign Minister signs a boundary treaty with State BB after State BB's agents show him photographs threatening his family. A separate article of the same treaty obliges State AA to supply forced labour for State BB's mines. State AA performs for two years and then, on a change of government, says the whole treaty is a nullity. State BB replies that State AA acquiesced.

The coercion of the representative. Article 51: consent procured by coercion of a representative through acts or threats directed against him is without any legal effect. Note that article 51 does not say the injured State may invoke it; it says the expression of consent has no effect.

Acquiescence. Article 45 lists articles 46 to 50 and articles 60 and 62. Article 51 is not in the list, so two years of performance does not bar State AA.

Severance. Article 44(5): in cases under articles 51, 52 and 53 no separation is permitted. State AA cannot keep the boundary and drop the labour article, nor can State BB save the parts it likes.

The forced labour article independently. Article 53: a treaty is void if at the time of its conclusion it conflicts with a peremptory norm, and the prohibition of slavery and forced labour is among the norms generally accepted as peremptory. Again article 44(5) forbids severance, so the whole treaty is void on this ground too.

Procedure. Article 65 requires State AA to notify State BB of its claim, the measure proposed and the reasons, and to wait three months unless the case is one of special urgency. If State BB objects, article 65(3) sends them to Charter article 33, and after twelve months article 66(a) lets either of them take the jus cogens question to the International Court by written application.

Consequences. Article 69(1) makes the treaty void with no legal force. Article 69(2)(a) lets State AA require restoration of the position as far as possible. Article 69(3) denies State BB the protection of good faith, since the coercion is imputable to it. Article 71(1) requires the elimination of the consequences of the forced labour and conformity with the peremptory norm.

Change one fact: the treaty was valid when made, and a new peremptory norm emerges afterwards. Then article 64 applies, the treaty becomes void and terminates from that point rather than being void from the beginning, and article 71(2) governs what survives.

Distinctions table

What it does NOT mean

A treaty is not invalid for unfairness. Article 42(1) confines impeachment to grounds in the Convention, and inequality of bargaining is not one.

Article 46 is not a general defence of unconstitutionality. The violation must be manifest and concern a rule of fundamental importance, and manifest is judged objectively from outside.

Error of law is not error under article 48, nor is error the State's own conduct contributed to, nor an error of wording.

Article 52 is not settled as covering economic coercion. The text points to Charter force, and the conference left the wider question open.

Jus cogens is not a list in the Convention. Article 53 states a definition, and the examples come from practice and commentary.

Article 64 does not void the treaty from the start. It makes it become void and terminate.

Invalidity does not erase the customary rule. Article 43 preserves obligations binding independently of the treaty.

Limits and criticism

Article 53 defines jus cogens without identifying a single norm, so the category is at once the most powerful in the law of treaties and the least determinate. States accepted the definition precisely because it named nothing.

Article 66 is the only compulsory jurisdiction in the Convention, and several States refused to ratify because of it, while others reserved against it. The result is that the enforcement of the most fundamental rule depends on a procedure many of the States most likely to be accused have declined.

Article 52 leaves the economic coercion question open at exactly the point where developing States pressed hardest, and the Declaration adopted alongside the Convention has no operative force.

The invalidity grounds are almost never invoked successfully. Error has failed on the facts in the leading boundary cases; fraud and corruption are close to unused. The practical value of Part V lies in what it forbids rather than in what it has undone.

Quick revision

Article 42: validity may be impeached only through the Convention. Article 43: obligations binding independently of the treaty survive.

Article 44: severance only if the clauses are separable, were not an essential basis of consent, and continued performance would not be unjust; no severance under 51, 52, 53. Article 45: acquiescence bars 46 to 50, 60 and 62, and not 51 to 53.

Voidable: 46 internal law, only if manifest and of fundamental importance, manifest being objectively evident; 47 unnotified specific restriction; 48 error of fact forming an essential basis, barred by own conduct or notice, wording errors excluded; 49 fraud; 50 corruption by a negotiating State.

Void: 51 coercion of the representative, without any legal effect; 52 coercion of the State by threat or use of force contrary to the Charter; 53 conflict with a peremptory norm.

Article 53 definition: accepted and recognised by the international community of States as a whole, no derogation permitted, modifiable only by a later norm of the same character. Article 64: a new peremptory norm makes an existing treaty become void and terminate.

Procedure: 65 notify, three months, objection sends the parties to Charter article 33; 66 after twelve months, jus cogens goes to the International Court, everything else to Annex conciliation; 67 writing and instrument; 68 revocable before it takes effect.

Consequences: 69 void, no legal force, restoration as far as possible, good faith protected except for the party responsible for fraud, corruption or coercion; 71 eliminate the consequences and conform to the peremptory norm.

Test yourself

1. On what grounds may the validity of a treaty be impeached?

Only on the grounds stated in the Vienna Convention, because article 42(1) provides that validity may be impeached only through the application of the Convention. The grounds are article 46, consent expressed in manifest violation of a rule of internal law of fundamental importance on competence to conclude treaties; article 47, breach of a specific restriction on authority notified beforehand; article 48, error of fact forming an essential basis of consent; article 49, fraud; article 50, corruption of the representative; article 51, coercion of the representative; article 52, coercion of the State by the threat or use of force; and article 53, conflict with a peremptory norm. The first five make consent voidable at the instance of the injured State; the last three operate absolutely.

2. Define jus cogens and explain its effect on a treaty.

Article 53 defines a peremptory norm of general international law as a norm accepted and recognised by the international community of States as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character. A treaty is void if at the time of its conclusion it conflicts with such a norm, and by article 44(5) no separation of its provisions is permitted, so the whole treaty falls. By article 64, if a new peremptory norm emerges, an existing treaty in conflict with it becomes void and terminates, which operates from the emergence of the norm rather than from the beginning. Article 71 then requires the parties to eliminate as far as possible the consequences of acts performed in reliance on the conflicting provision and to bring their relations into conformity with the norm.

3. Distinguish articles 51 and 52.

Article 51 concerns coercion of the representative, through acts or threats directed against him personally, and provides that the expression of consent so procured shall be without any legal effect. Article 52 concerns coercion of the State itself, and provides that a treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations. Both are absolute, so no severance is permitted under article 44(5) and acquiescence under article 45 cannot cure them. Article 52 is historically the more important, because it reversed the old law under which a peace treaty imposed by a victor was valid.

4. When can a State plead its own constitution to invalidate its consent?

Rarely. Article 46 permits it only where the consent was expressed in violation of a provision of internal law regarding competence to conclude treaties, and only where the violation was manifest and concerned a rule of internal law of fundamental importance. Article 46(2) makes the test of manifestness objective: a violation is manifest if it would be objectively evident to any State conducting itself in the matter in accordance with normal practice and in good faith. The rule is deliberately narrow because article 27 forbids invoking internal law as a justification for failure to perform, and because States cannot be expected to audit each other's constitutional arrangements.

5. What procedure must a State follow before treating a treaty as invalid?

Article 65 requires it to notify the other parties of its claim, indicating the measure proposed and the reasons. If no objection is raised within a period which, except in cases of special urgency, shall not be less than three months from receipt, it may carry out the measure through a written instrument under article 67. If objection is raised, the parties must seek a solution through the means indicated in Article 33 of the Charter. If no solution is reached within twelve months of the objection, article 66 provides that a dispute about article 53 or 64 may be submitted by any party to the International Court of Justice by written application unless they agree on arbitration, while a dispute about any other article of Part V may be taken to the conciliation procedure in the Annex by request to the Secretary-General.

6. A treaty procured by fraud is declared invalid after five years of performance. What happens to what was done?

Article 69(1) makes the treaty void with no legal force. Article 69(2)(a) permits each party to require any other to establish, as far as possible in their mutual relations, the position that would have existed if the acts had not been performed. Article 69(2)(b) protects acts performed in good faith before the invalidity was invoked, so they are not rendered unlawful by reason only of the invalidity. But article 69(3) withdraws that protection from the party to which the fraud is imputable, so the defrauding State cannot rely on its own good faith. Article 43 separately preserves any obligation in the treaty that binds the States under international law independently of it.