UNIVERSITY OF CAMBRIDGE
INTERNATIONAL LAW, 2018-2019
The Law of Treaties
Lectures 4-6
Overview
The Notion of ‘Treaty’.....................................................................................1
Conclusion of Treaties.....................................................................................2
Validity of Treaties..........................................................................................2
A. Reservations to Treaties.....................................................................................3
Treaty Interpretation.......................................................................................7
Treaty Performance.........................................................................................9
B. Treaty Termination/Suspension......................................................................10
66. Distinguish circumstances precluding wrongfulness in the law for state
responsibility (see Lent Term) and the grounds for termination of treaties.....10
Material breach..........................................................................................................10
Bilateral Treaties........................................................................................................11
Supervening Impossibility of Performance..............................................................11
Fundamental change of circumstances (clausula rebus his stantibus)..................11
e Notion of ‘Treaty’
1. Point of departure: Vienna Convention on the Law of Treaties
1969 (‘VCLT’), 1155 UNTS 331.
Cf. also Convention on the Law of Treaties between States
and International Organizations or between International
Organizations 1986 (not in force)
2. Example of a major multilateral treaty: 1948 Convention on
the Prevention and Punishment of Genocide (‘Genocide
Convention’). The Genocide Convention had 41 signatories in
1948 and has grown to 149 state parties today.
3. Definition of ‘treaty’: Article 2(1)(a) VCLT
4. VCLT does not govern oral agreements between states:
Articles 3(a) and (b) VCLT.
5. Intention to Create Legal Relations
Memoranda of Understanding and other written, soft
law instruments
INTERNATIONAL LAW, 2018-2019
The Law of Treaties
Lectures 4-6
Overview
The Notion of ‘Treaty’.....................................................................................1
Conclusion of Treaties.....................................................................................2
Validity of Treaties..........................................................................................2
A. Reservations to Treaties.....................................................................................3
Treaty Interpretation.......................................................................................7
Treaty Performance.........................................................................................9
B. Treaty Termination/Suspension......................................................................10
66. Distinguish circumstances precluding wrongfulness in the law for state
responsibility (see Lent Term) and the grounds for termination of treaties.....10
Material breach..........................................................................................................10
Bilateral Treaties........................................................................................................11
Supervening Impossibility of Performance..............................................................11
Fundamental change of circumstances (clausula rebus his stantibus)..................11
e Notion of ‘Treaty’
1. Point of departure: Vienna Convention on the Law of Treaties
1969 (‘VCLT’), 1155 UNTS 331.
Cf. also Convention on the Law of Treaties between States
and International Organizations or between International
Organizations 1986 (not in force)
2. Example of a major multilateral treaty: 1948 Convention on
the Prevention and Punishment of Genocide (‘Genocide
Convention’). The Genocide Convention had 41 signatories in
1948 and has grown to 149 state parties today.
3. Definition of ‘treaty’: Article 2(1)(a) VCLT
4. VCLT does not govern oral agreements between states:
Articles 3(a) and (b) VCLT.
5. Intention to Create Legal Relations
Memoranda of Understanding and other written, soft
law instruments
