• Grounds

– Lack of competence to conclude the treaty [Arts. 46 & 47]

– Error [Art. 48]

– Fraud [Art. 49]

– Corruption of a representative of a State [Art. 50]

– Coercion of a representative of a State [Art. 51]

– Coercion of a State by the threat or use of force [Art. 52]

– Treaties conflicting with a peremptory norm [Art. 53]

Lack of Competence
• Lack of competence to conclude the treaty [Arts. 46 & 47]

– Art. 46

Representative exceeded their treaty making powers under internal law cannot be invoked unless such excess of authority was :

• Clear/obvious– i.e. objectively evident to other state acting in accordance with normal practice and in good faith

• Concerned a rule of internal law of fundamental importance

– Art. 47  case where a representative’s authority is subject to a specific limitation in point of fact; excess of authority is then not sufficient to invalidate that action unless the specific restriction on authority was notified beforehand to the other states.
Error (art. 48)
• If the error be one as to a fact or situation assumed by the state concerned to exist at the time when the treaty was concluded, and which formed an essential basis of consent to the treaty

• Recorded instances – geographical error, / errors in maps

• Limitation ( Not open to state ) – if it contributed to the error by its own conduct – Or the circumstances were such as to put it upon notice of a possible error – Or the error related only to the wording of the text of the treaty

• No explicit reference to an error of law, although speaks of error relating to ‘situation’ or ‘fact’

• No distinction between unilateral error, on the one hand, and common or mutual error, on the other hand
Fraud (art. 49)
• Induced by fraudulent conduct of another state to enter into the treaty

• Fraud ?? Not defined by VCLT

• Lack of precedent to define fraud

Corruption (Art. 50)
• Consent has been procured through corruption of its representative

• Directly or indirectly

• state is entitled to claim that treaty is invalid
Coercion (Art. 51-52)
• Elements:

– A state’s consent has been procured by coercion of its representatives through acts or threats directed against them – Conclusion of treaty has been procured by threat or use of force in violation of principle of international law embodied in UN charter

• Force – may be economic or political pressure

Conflict with jus cogens (Art. 53)
• void if, at the time of its conclusion, it conflicts with a peremptory norm of general international law. – peremptory norm of general international law is a norm accepted and recognized 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.

Right to invalidate treaty

– (WAIVED) (Is lost) if subsequently the state expressly agrees that the treaty is valid or remains in force – Or its conduct is such as to lead to the inference of agreement in the continued validity or application of treaty (art. 45) • If want to invalidate – Must notify other parties of its claim – Procedure laid down in art 65-66 may be follo