international law

1. Lecture 4 & 5
The Law of Treaties

2. LAW OF TREATIES
• Introduction
• Codification of the Law of Treaties
• Definition
• Conclusion of Treaties
• Reservations
• Registration and Publication
• Observance, Application and Interpretation of Treaties
• Treaties and Third States
• Invalidity of Treaties
• Termination of Treaties
• Supplementary Reading

3. 1) Introduction
• Treaties are the principle source of
international rights and obligations.
• Every State is a party to hundreds of treaties,
bilateral and multilateral.
• Treaties regulate practically every aspect of
State behavior in times of peace and in times
of war.

4. 2) Codification of the Law of Treaties
• The law of treaties has been codified. The Vienna Convention on the Law
of Treaties was signed at Vienna on 23 May 1969 and entered into force
on 27 January 1980 after being ratified by 35 States.
• The Preamble to the 1969 Vienna Convention provides, however, that
“the rules of customary international law will continue to govern
questions not regulated by the provisions of the present Convention”.
• The 1969 Vienna Convention on the Law of Treaties applies only to
treaties concluded by States. An additional treaty dealing with treaties
concluded between States and international organizations or between
international organizations was signed in 1986 in Vienna. It has not yet
entered into force.

5. VIENNA CONVENTION ON THE LAW OF
TREATIES 1969 (VCLT)
• PART I – INTRODUCTION
• Article 1 - Scope of the present Convention
• Article 2 - Use of terms
• Article 3 - International agreements not within the scope of the
present Convention
• Article 4 - Non-retroactivity of the present Convention
• Article 5 - Treaties constituting international organizations and
treaties adopted within an international organization

6. • PART II - CONCLUSION AND ENTRY INTO FORCE OF TREATIES
• SECTION 1 - CONCLUSION OF TREATIES
• Article 6 -Capacity of States to conclude treaties
• Article 7 - Full powers
• Article 8 - Subsequent confirmation of an act performed without
authorization
• Article 9 - Adoption of the text

7. • Article 10 - Authentication of the text
• Article 11 - Means of expressing consent to be bound
by a treaty
• Article 12 - Consent to be bound by a treaty
expressed by signature
• Article 13 - Consent to be bound by a treaty
expressed by an exchange of instruments constituting
a treaty

8. • Article 14 - Consent to be bound by a treaty expressed by
ratification, acceptance or approval
• Article 15 - Consent to be bound by a treaty expressed by
accession
• Article 16 - Exchange or deposit of instruments of ratification,
acceptance, approval or accession
• Article 17 - Consent to be bound by part of a treaty and choice of
differing provisions
• Article 18 - Obligation not to defeat the object and purpose of a
treaty prior to its entry into force

9. • SECTION 2 - RESERVATIONS
• Article 19 - Formulation of reservations
• Article 20 - Acceptance of and objection to reservations
• Article 21 - Legal effects of reservations and of objections to
reservations
• Article 22 - Withdrawal of reservations and of objections to
reservations
• Article 23 - Procedure regarding reservations

10. • SECTION 3 - ENTRY INTO FORCE AND
PROVISIONAL, APPLICATION OF TREATIES
• Article 24 - Entry into force
• Article 25 - Provisional application

11. • PART III -OBSERVANCE,APPLICATION AND
INTERPRETATION OF TREATIES
• SECTION 1 . OBSERVANCE OF TREATIES
• Article 26 - “Pacta sunt servanda”
• Article 27 - Internal law and observance of
treaties

12. • SECTION 2 - APPLICATION OF TREATIES
• Article 28 - Non-retroactivity of treaties
• Article 29 - Territorial scope of treaties
• Article 30 - Application of successive treaties
relating to the same subject matter

13. • SECTION 3 - INTERPRETATION OF TREATIES
• Article 31 - General rule of interpretation
• Article 32 - Supplementary means of interpretation
• Article 33 - Interpretation of treaties authenticated in two or more languages
• SECTION 4 - TREATIES AND THIRD STATES
• Article 34 - General rule regarding third States
• Article 35 - Treaties providing for obligations for third States

14. • Article 36 - Treaties providing for rights for third States
• Article 37 - Revocation or modification of obligations or rights of third States
• Article 38 - Rules in a treaty becoming binding on third States through international custom
• PART IV - AMENDMENT AND MODIFICATION OF TREATIES
• Article 39 - General rule regarding the amendment of treaties
• Article 40 - Amendment of multilateral treaties
• Article 41 - Agreements to modify multilateral treaties between certain of the parties only
• PART V - INVALIDITY, TERMINATION AND SUSPENSION OF THE OPERATION OF TREATIES
• SECTION 1 - GENERAL PROVISIONS
• Article 42 - Validity and continuance in force of treaties

15. • Article 43 - Obligations imposed by international law independently of a treaty
• Article 44 - Separability of treaty provisions
• Article 45 - Loss of a right to invoke a ground for invalidating, terminating,
withdrawing from or suspending the operation of a treaty
• SECTION 2 - INVALIDITY OF TREATIES
• Article 46 - Provisions of internal law regarding competence to conclude treaties
• Article 47 - Specific restrictions on authority to express the consent of a State
• Article 48 - Error
• Article 49 - Fraud

16. • Article 50 - Corruption of a representative of a State
• Article 51 - Coercion of a representative of a State
• Article 52 - Coercion of a State by the threat or use of force
• Article 53 - Treaties conflicting with a peremptory norm of general international law (“jus
cogens”)
• SECTION 3 - TERMINATION AND SUSPENSION OF THE OPERATION OF TREATIES
• Article 54 - Termination of or withdrawal from a treaty under its provisions or by consent of the
parties
• Article 55 - Reduction of the parties to a multilateral treaty below the number necessary for its
entry into force
• Article 56 - Denunciation of or withdrawal from a treaty containing no provision regarding
termination, denunciation or withdrawal

17. • Article 57 - Suspension of the operation of a treaty under its provisions or by consent of the
parties
• Article 58 - Suspension of the operation of a multilateral treaty by agreement between certain of
the parties only
• Article 59 - Termination or suspension of the operation of a treaty implied by conclusion of a
later treaty
• Article 60 - Termination or suspension of the operation of a treaty as a consequence of its breach
• Article 61 - Supervening impossibility of performance
• Article 62 - Fundamental change of circumstances
• Article 63 - Severance of diplomatic or consular relations
• Article 64 - Emergence of a new peremptory norm of general international law (“jus cogens”)

18. • SECTION 4 - PROCEDURE
• Article 65 - Procedure to be followed with respect to invalidity,
termination, withdrawal from or suspension of the operation of a
treaty
• Article 66 - Procedures for judicial settlement, arbitration and
conciliation
• Article 67 - Instruments for declaring invalid, terminating,
withdrawing from or suspending the operation of a treaty
• Article 68 - Revocation of notifications and instruments provided
for in articles 65 and 67

19. • SECTION 5 - CONSEQUENCES OF THE INVALIDITY, TERMINATION
• OR SUSPENSION OF THE OPERATION OF A TREATY
• Article 69 - Consequences of the invalidity of a treaty
• Article 70 - Consequences of the termination of a treaty
• Article 71 - Consequences of the invalidity of a treaty which conflicts with a peremptory norm of general
international law
• Article 72 - Consequences of the suspension of the operation of a treaty
• PART VI - MISCELLANEOUS PROVISIONS
• Article 73 - Cases of State succession, State responsibility and outbreak of hostilities
• Article 74 - Diplomatic and consular relations and the conclusion of treaties
• Article 75 - Case of an aggressor State

20. • PART VII - DEPOSITARIES, NOTIFICATIONS, CORRECTIONS AND REGISTRATION
• Article 76 - Depositaries of treaties
• Article 77 - Functions of depositaries
• Article 78 - Notifications and communications
• Article 79 - Correction of errors in texts or in certified copies of treaties
• Article 80 - Registration and publication of treaties
• PART VIII - FINAL PROVISIONS
• Article 81 – Signature
• Article 82 – Ratification
• Article 83 – Accession
• Article 84 - Entry into force
• Article 85 - Authentic texts
• ANNEX

21. 3) : Definition
• Article 2 p. 1(a) of the VCLT defines “treaty” as
– an international agreement concluded
between States
– in written form,
– governed by international law,
–whether embodied in a single instrument or
in two or more related instruments and
–whatever its particular designation.

22. • This definition was formulated for the purposes of
the Vienna Convention and does not define treaties
at large.
• Other names commonly used for treaties include:
convention, charter, protocol, memorandum,
exchange of notes, declaration, covenant,
agreement, pact etc. The name given to a treaty may
indicate its significance, however, it does not affect
its legal character.

23. 4) Conclusion of Treaties
• The process of concluding a treaty may
vary depending on its subject matter and
the number of parties involved (bilateral
treaties, multilateral treaties).
• Every State possesses capacity to
conclude treaties.

24. • In the process of concluding international treaties States
act through their representatives. State representatives
have to produce full powers.
• “Full powers” means a document emanating from the
competent authority of a State designating a person or
persons to represent the State for negotiating, adopting or
authenticating the text of a treaty, for expressing the
consent of the State to be bound by a treaty, or for
accomplishing any other act with respect to a treaty.
• Heads of State, Heads of Government and Ministers for
Foreign Affairs, by virtue of their functions, can perform all
acts relating to the conclusion of a treaty without having to
produce full powers (Article 7).

25. • The process of the conclusion of treaties
consists of several stages including:
negotiations, adoption of the text of a
treaty, authentication of the text of a
treaty and expressing consent to be
bound by a treaty.

26. • The consent of a State to be bound by a treaty
may be expressed by:
– Signature (Article 12);
– Exchange of instruments constituting a
treaty (Article 13);
– Ratification, acceptance or approval (Article
14);
– Accession (Article 15).

27. • The final stage of the process of the
conclusion of treaties is entry into force.
• Treaties enter into force in such manner and
upon such date as is provided by the treaty
itself or as it is agreed by the parties.

28. Examples:
• The 1969 Vienna Convention on the Law of
Treaties entered into force on the thirtieth
day following the submission of the thirty-fifth
instrument of ratification.
• The 1982 United Nations Convention on the
Law of the Sea entered into force 12 months
after the date of deposit of the sixtieth
instrument of ratification or accession.

29. 5) Reservations
• A State may, while signing, ratifying,
accepting, approving or acceding to a treaty,
formulate a reservation.
• Reservation means a unilateral statement,
however phrased or named, made by a State
by which it intends to exclude or to modify the
legal effect of certain provisions of the treaty
in their application to that State (Article 2).

30. • Formulating reservations is permitted unless the
reservation is prohibited by the treaty or is
incompatible with the object and purpose of the
Treaty.
• Other States may accept or object to
reservations.
• Article 309 of the 1982 Convention on the Law of
the Sea provides that “No reservations or
exceptions may be made to this Convention
unless expressly permitted by the articles of this
Convention”.

31. 6) Registration and Publication
• Treaties concluded by the Member States of the
United Nations have to be registered with the
Secretariat of the United Nations.
• Article 102 of the Charter of the United Nations
provides that
“Every treaty and every international agreement
entered into by any Member of the United Nations
after the present Charter comes into force shall as
soon as possible be registered with the secretariat
and published by it”.

32. • All treaties registered are published in the
United Nations Treaty Series
(http://www.un.org/) and translated into
world languages, if necessary.
• There are more than 30 000 treaties
registered and published since 1945.

33. 7) Observance, Application and
Interpretation of Treaties
• Every treaty in force is binding upon the parties
to it and must be performed by them in good
faith (pacta sunt servanda - Article 26).
• In principle, a treaty is binding upon each party in
respect of its entire territory (Article 29).
• There are, however, treaties which application is
localized (e.g. treaties establishing servitudes,
navigation rights on international rivers or
canals).

34. • The general rule of interpretation of treaties is that
treaties shall be interpreted in good faith in
accordance with the ordinary meaning to be given to
the terms of the treaty in their context and in the light
of its object and purpose (Article 31).
• To confirm the meaning of a treaty, recourse may be
made to supplementary means of interpretation such
as the preparatory work of the treaty and the
circumstances of its conclusion.
• Interpretation of treaties authenticated in two or more
languages may pose special difficulties. The text of
such treaty is equally authoritative in each language.

35. 8) Treaties and Third States
• In principle, a treaty does not create either
obligations or rights for a State which is not a
party to that treaty (Article 34).
• In exceptional circumstances, a treaty may
provide for obligation for third States if they
expressly accept that obligation in writing
(Article 35).

36. • A treaty may also provide for rights for the
third State, a group of States or to all States if
the third States assent thereto. Their assent
may be presumed (Article 36).
• An example of a treaty providing for rights for
all States is 1936 Montreux Convention
providing for the freedom of navigation on the
Turkish Straits.

37. 9) Invalidity of Treaties
• The validity of a treaty or the consent to be
bound by a treaty may be impeached.
• Invalidity eradicates legal effects of the treaty.

38. The reasons which may lead to invalidity of
treaties include:
1. a manifest non-compliance with
municipal law of fundamental importance,
regarding competence to conclude treaties
(Article 46);
2. omission of restrictions of authority of a
State representative, if the restriction was
notified to the other negotiating States
(Article 47);

39. 3. error, if related to the fact or situation
which was assumed by a State to exist at the
time when the treaty was concluded and
formed an essential basis of its consent to be
bound by the treaty (Article 48);
4. fraudulent conduct of another negotiating
State (Article 49);

40. 5. corruption of a representative of a State
(Article 50).
6. A treaty is automatically invalid (null and
void) if: the expression of a State’s consent to
be bound by a treaty has been procured by
the coercion of its representative through acts
or threats directed against him (Article 51);

41. 7. 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 (Article
52);
8. at the time of its conclusion, it conflicts with a
peremptory norm (jus cogens) of general international
law (Article 53).
A peremptory norm of general international law is a
norm accepted and regognised 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.

42. 10) Termination of Treaties
• The termination of a treaty (or the withdrawal
from a treaty) may take place in conformity
with its provisions or by the consent of all the
parties to that treaty (Article 54).
• Also, a treaty terminates if all the parties to it
conclude a new treaty relating to the same
subject matter.

43. • A treaty may also be terminated:
1. as a consequence of its material breach by
one of the parties (Article 60);
2. because of the supervening impossibility of
performance resulting from the permanent
disappearance or destruction of an object
indispensable for the execution of the treaty
(Article 61);

44. 3. in case of a fundamental change of
circumstances existing at the time of the
conclusion of the treaty, provided the existence
of those circumstances constituted an essential
basis of the consent of the parties to be bound by
the treaty and the effect of the change is to
radically transform their remaining obligations.
However, the fundamental change of
circumstances cannot be invoked to terminate a
treaty establishing a boundary or if the
fundamental change is the result of a breach of
an obligation.

45. Supplementary Reading
• Chin Lim and Elias Olufemi, “The Role of Treaties in the Contemporary
International Legal Order”, Nordic Journal of International Law, Vol.
66, 1997, pp.1-21.
• Richard D. Kearney and Robert E. Dalton, “The Treaty of Treaties”,
American Journal of International Law, Vol. 64, No. 3, June 1970, pp.
495-561.
• S.E. Nahlik, “The Ground of Invalidity and Termination of Treaties”,
American Journal of International Law, Vol. 65, No. 4, October 1971,
pp. 736-756.
• Jan.Klabbers, The concept of treaty in international law (The Hague:
Kluwer, 1996).