Public International Law: Chapter III — The Law of Treaties (September 27, 2023)

 Chapter III — The Law of Treaties 

Various Names of Treaties 

• conventions
• pacts
• covenants
• charters
• protocols
• concordat
• modus vivendi
• international agreements ー generic term

Treaties

• represent the most deliberate form of commitment through which governments cooperate with one another
• convenient tool through which states are able to project common expectations in the absence of an international legislative body

 1969 Vienna Convention on the Law of Treaties

• where the law on treaties is found
• governs treaties between states
• entered into force in January 1980
• not retroactive in effect, but it does contain customary law precepts antedating 1969

Definition of treaties.

1969 Vienna Convention:

“an international agreement 
concluded between States 

in written form 

and governed by international law, 
whether embodied in a single instrument 

or in two or more related instruments 

and whatever its particular designation.” 

• applies to international agreements that satisfy the Convention’s definition
• specifically that:
• they be in writing
• reflective of the intention of the parties to be bound
• governed by international law
• while treaties are generally in written form, there are writers who hold that even an oral agreement can be binding
• only written agreements that are new, come under the provisions of the Vienna Convention
• no particular form is prescribed
• Qatar v. Bahrain
• exchange of notes between the two heads of state was considered an international agreement
• Norway v. Denmark
• Facts: 
• Denmark had offered certain concessions important for Norway for the purpose of persuading Norway not to obstruct Danish plans in regard to Greenland. 
• In reply, the Norwegian Minister accepted the offer: “I told the Danish Minister today that the Norwegian Government would not make any difficulty in the settlement of this question.” 
• The Court found this declaration sufficient to bind the Norwegian government.
• Nuclear Test Cases: Australia v. France, New Zealand v. France
• even a unilateral declaration concerning legal or factual situations may create legal obligations
• Facts: 
• France was a signatory to the Nuclear Test Ban Treaty and thus continued to conduct tests in the South Pacific until 1973. The tests conducted in 1972 and 1973 led to the filing of protests by Australia and New Zealand. 
• The case, however, was taken off the Court’s list without a decision when France announced by a series of unilateral announcements that it would conduct no further tests after 1973. 
• The Court nevertheless commented on the legal significance of these announcements saying:
• It is well-recognized that declarations made by way of unilateral acts concerning legal or factual situations, may have the effect of creating legal obligations. Declarations of this kind may be, and often are, very specific. When it is the intention of the State making the declaration that it should become bound according to its terms, that intention confers on the declaration the character of a legal undertaking, the State being thenceforth legally required to follow a course of conduct consistent with the declaration. An undertaking of this kind, if given publicly, and with an intent to be bound, even though not made within the context of international negotiations, is binding...
• In announcing that the 1974 series of atmospheric tests would be the last, the French Government conveyed to the world at large ... its intention to terminate these tests. It was bound to assume that other States might take note of these statements and rely on their being effective. The validity of these statements and their legal consequences must be considered within the general framework of the security of international intercourse, and the confidence and trust which are so essential in the relations among States.
• This, however, did not prevent France from conducting nuclear tests in the South Pacific. After having conducted six nuclear tests, France responded to worldwide outrage and stopped the testing at six in 1996 rather than the originally planned eight.
• Two characteristics the Court found which convinced it that a binding obligation had been incurred:
• First, the commitment was very specific;
• Second, there was a clear intent to be bound.
• Trade Act of 1974 (European Union v. USA, 1999)
• care in attributing binding effect to a unilateral declaration was expressed
•  7.118 Attributing international legal significance to unilateral statements made by a State should not be done lightly and should be subject to strict conditions. Although the legal effects we are ascribing to the US statements made to the DSB [Dispute Settlement Body] through this Panel are of a more narrow and limited nature and reach compared to other internationally relevant instances in which legal effect was given to unilateral declarations, we have conditioned even these limited effects on the fulfillment of the most stringent criteria. A sovereign State should normally not find itself legally affected on the international plane by the casual statement of any of the numerous representative speaking on its behalf in today’s highly interactive and inter-dependent world nor by a representation made in the heat of legal argument on a State’s behalf. This, however, is very far from the case before us.
• 7.121 The statements made by the US before this Panel were a reflection of official US policy, intended to express US understanding of its international obligations as incorporated in domestic US law. The statements did not represent a new US policy or undertaking but the bringing of a pre-existing US of a pre-existing US policy and undertaking made in a domestic setting into an international forum.

Function of treaties. 

• sources of international law
• serve as the charter of international organizations
• used to transfer territory
• regulate commercial relations
• settle disputes
• protect human rights
• guarantee investments, etc. 

Different Kinds of Treaties Classified from their Relevance as Source of International Law

1. Multilateral treaties 

• open to all states of the world
• create norms which are the basis for a general rule of law
• either codification treaties or “law-making treaties” or they may have the character of both
• treaties that are made between three or more states
• most common type of treaty, often used to address complex issues that require cooperation from multiple states.
• examples: 
• United Nations Charter is a multilateral treaty that establishes the United Nations and sets out its goals and principles
• World Trade Organization Agreement is a multilateral treaty that establishes the World Trade Organization and sets out the rules for international trade

2. Treaties that create a collaborative mechanism

• can be of universal scope {e.g., regulation of allocation of radio frequencies) or regional (e.g fishing agreements)
• operate through the organs of the different states
• type of multilateral treaty that is designed to promote cooperation between states on a specific issue
• used to address complex issues that require the input and expertise of multiple states
• examples:
• ASEAN Trade in Goods Agreement (ATIGA) is a collaborative treaty that aims to reduce tariffs and other trade barriers between ASEAN member states
• Paris Agreement on Climate Change is a collaborative treaty that aims to reduce greenhouse gas emissions and mitigate the effects of climate change

3. Bilateral treaties

• largest category of treaties
• many are in the nature of contractual agreements which create shared expectations such as trade agreements of various forms
• sometimes called “contract treaties” 
• treaties that are made between two states
• typically used to address issues of specific interest to the two states involved
• example: 
• Mutual Defense Treaty (United States–Philippines)

While treaties are generally binding only on the parties, the number of the contracting parties and the generality of the acceptance of specific rules created by the treaty can have the effect of creating universal law in much the same way that general practice suffices to create customary law.

The making of treaties

1. Negotiation

• bilateral treaties, and multilateral treaties among a small number, generally originate from the foreign ministries
• negotiation is done through foreign ministries
• larger multilateral treaties are negotiated in diplomatic conferences which are run like a legislative body
• the negotiators must possess powers to negotiate
• an act relating to the conclusion of a treaty by one who has no proper authorization has no legal effect unless confirmed by his state:

Article 7. Full powers.

1. A person is considered as representing a State for the purpose of adopting or authenticating the text of a treaty or for the purpose of expressing the consent of the State to be bound by a treaty if:

        (a) he produces appropriate full powers; or

        (b) it appears from the practice of the States concerned 

or from other circumstances that their intention was to consider that person as representing the State for such purposes and to dispense with full powers.

2. In virtue of their functions and without having to produce full powers, the following are considered as representing their State:

        (a) Heads of State, Heads of Government and Ministers for Foreign Affairs, for the purpose of performing all acts relating to the conclusion of a treaty;

        (b) heads of diplomatic missions, for the purpose of adopting the text of a treaty between the accrediting State and the State to which they are accredited;

        (c) representatives accredited by States to an international conference or to an international organization or one of its organs, for the purpose of adopting the text of a treaty in that conference, organization or organ

2. Authentication of text

• negotiations conclude with the signing of the document
• the signatures serve as authentication of the document

Article 9. Adoption of the text:

1. The adoption of the text of a treaty takes place by the consent of all the States participating in its drawing up except as provided in paragraph 2.

2. The adoption of the text of a treaty at an international conference takes place by the vote of two-thirds of the States present and voting, unless by the same majority they shall decide to apply a 

different rule.

Article 10. Authentication of the text:

The text of a treaty is established as authentic and definitive:

        (a) by such procedure as may be provided for in the text or agreed upon by the States participating in its drawing up; or

        (b) failing such procedure, by the signature, signature ad referendum or initialing by the representatives of those States of the text of the treaty or of the Final Act of a conference incorporating the text.

The authentication of a treaty makes the text authoritative and definitive. It is necessary so that the states will know definitively the contents of the text and avoid any misunderstanding as to the terms.

3. Consent to be bound

• once the document has been signed, there are stages which follow which culminate in making the document binding
• the most important step is the consent to be bound
• there are various ways by which consent to be bound is expressed:

Article 11. Means of expressing consent to be bound by a treaty:

The consent of a State to be bound by a treaty may be expressed by signature, exchange of instruments constituting a treaty, ratification, acceptance, approval or accession, or by any other means if so agreed.

Article 12. Consent to be bound by a treaty expressed by signature:

1. The consent of a State to be bound by a treaty is expressed by the signature of its representative when:

        (a) the treaty provides that signature shall have that effect; 

        (b) it is otherwise established that the negotiating States were agreed that signature should have that effect; or

        (c) the intention of the State to give that effect to the signature appears from the full powers of its representative or was expressed during the negotiation.

2. For the purposes of paragraph 1:

        (a) the initialing of a text constitutes a signature of the treaty when it is established that the negotiating States so agreed; 

        (b) the signature and referendum of a treaty by a representative, if confirmed by his State, constitutes a full signature of the treaty.

Article 13. Consent to be bound by a treaty expressed by an exchange of instruments constituting a treaty:

The consent of States to be bound by a treaty constituted by instruments exchanged between them is expressed by that exchange when:

        (a) the instruments provide that their exchange shall have 

that effect; or 

        (b) it is otherwise established that those States were agreed that the exchange of instruments should have that effect, xxx

Article 14. Consent to be bound by a treaty expressed by ratification, acceptance or approval:

1. The consent of a State to be bound by a treaty is expressed by ratification when: 

        (a) the treaty provides for such consent to be expressed by means of ratification; 

        (b) it is otherwise established that the negotiating States were agreed that ratification should be 

required; 

        (c) the representative of the State has signed the treaty subject to ratification; or 

        (d) the intention of the State to sign the treaty subject to ratification appears from the full powers of its representative or was expressed during the negotiation.

2. The consent of a State to be bound by a treaty is expressed by acceptance or approval under conditions similar to those which apply to ratification.

• the manner of ratification differs from state to state
• in the Philippines, it is governed by Article VII, Section 21 of the Constitution
• but between signature and ratification a state is required by Article 18(a) not to engage in acts which can defeat the purpose of the treaty
• ratification is next followed by either exchange of ratification, in bilateral treaties, or, in multilateral treaties, deposit of ratification:

Article 16. Exchange or deposit of instruments of ratification, acceptance, approval or accession:

Unless the treaty otherwise provides, instruments of ratification, acceptance, approval or accession establish the consent of a State to be bound by a treaty upon:

        (a) their exchange between the contracting States; 

        (b) their deposit with the depositary; or 

        (c) their notification to the contracting States or to the depositary, if so agreed.

Article 17. Consent to be bound by part of a treaty and choice of 

differing provisions:

1. Without prejudice to Articles 19 to 23, the consent of a State to be bound by part of a treaty is effective only if the treaty so permits or the other contracting States so agree.

2. The consent of a State to be bound by a treaty which permits a choice between differing provisions is effective only if it is made clear to which of the provisions the consent relates.

Accession to a treaty

• States which did not participate in the initial negotiation may also express their consent to be bound by “accession.” 
• Article 15 of the Convention says:

The consent of a State to be bound by a treaty is expressed by accession when:
        (a) the treaty provides that such consent may be expressed by that State by means of accession;
        (b) it is otherwise established that the negotiating States were agreed that such consent may be expressed by that State by means of accession; or
        (c) all the parties have subsequently agreed that such consent may be expressed by that State by means of accession.

Reservations

• in deference to the sovereignty of states, the Vienna Convention allows for “reservations.”

Article 2 defines reservations as:

a unilateral statement, 

however phrased or named, 

made by a State, 

when signing, ratifying, accepting, approving or acceding to a treaty, 

whereby it purports to exclude or to modify the legal effect 

of certain provisions of the treaty in their application to that State.

• in this regard, treaties are different from statutes
• statutes must necessarily apply to all
• reservations, however, are different from “interpretative declarations” which are not meant to be a derogation from the treaty but an expression of how a state understands its adoption of the treaty
• the rules on reservations are found in Articles 19 to 23:

Article 19. Formulation of reservations.

A State may, when signing, ratifying, accepting, approving or acceding to a treaty, formulate a reservation unless:

        (a) the reservation is prohibited by the treaty; 

        (b) the treaty provides that only specified reservations, which do not include the reservation in question, may be made; or 

        (c) in cases not falling under sub-paragraphs (a) and (b), the reservation is incompatible with the 

object and purpose of the treaty.

Article 20. Acceptance of and objection to reservations

1. A reservation expressly authorized by a treaty does not require any subsequent acceptance by the other contracting States unless the treaty so provides.

2. When it appears from the limited number of the negotiating States and the object and purpose of a treaty that the application of the treaty in its entirety between all the parties is an essential condition of the consent of each one to be bound by the treaty, a reservation requires acceptance by all the parties.

3. When a treaty is a constituent instrument of an international organization and unless it otherwise provides, a reservation requires the acceptance of the competent organ of that organization.

4. In cases not falling under the preceding paragraphs and unless the treaty otherwise provides:

        (a) acceptance by another contracting State of a reservation constitutes the reserving State a party to the treaty in relation to that other State if or when the treaty is in force for those States;

        (b) an objection by another contracting State to a reservation does not preclude the entry into force of the treaty as between the objecting and reserving States unless a contrary intention is definitely expressed by the objecting State;

        (c) an act expressing a State’s consent to be bound by the treaty and containing a reservation is effective as soon as at least one other contracting State has accepted the reservation.

5. For the purposes of paragraphs 2 and 4 and unless the treaty otherwise provides, a reservation is considered to have been accepted by a State if it shall have raised no objection to the reservation by the end of a period of twelve months after it was notified of the reservation or by the date on which it expressed its consent to be bound by the treaty, whichever is later.

Article 21. Legal effects of reservations and of objections to reservations:

1. A reservation established with regard to another party in accordance with Articles 19,20 and 23:

        (a) modifies for the reserving State in its relations with that other party the provisions of the treaty to which the reservation relates to the extent of the reservation; and

        (b) modifies those provisions to the same extent for that other party in its relations with the reserving State.

2. The reservation does not modify the provisions of the treaty for the other parties to the treaty inter se.

3. When a State objecting to a reservation has not opposed the entry into force of the treaty between itself and the reserving State, the provisions to which the reservation relates do not apply as between the two States to the extent of the reservation.

Article 22. Withdrawal of reservations and of objections to reservations:

1. Unless the treaty otherwise provides, a reservation may be withdrawn at any time and the consent of a State which has accepted the reservation is not required for its withdrawal.

2. Unless the treaty otherwise provides, an objection to a reservation may be withdrawn at any time.

3. Unless the treaty otherwise provides, or it is otherwise agreed:

            (a) the withdrawal of a reservation becomes operative in relation to another contracting State only when notice of it has been received by that State; 

            (b) the withdrawal of an objection to a reservation becomes operative only when notice of it has been received by the State which formulated the reservation.

Article 23. Procedure regarding reservations:

1. A reservation, an express acceptance of a reservation and an objection to a reservation must be formulated in writing and communicated to the contracting States and other States entitled to become parties to the treaty.

2. If formulated when signing the treaty subject to ratification, acceptance or approval, a reservation must be formally confirmed by the reserving State when expressing its consent to be bound by the treaty. In such a case the reservation shall be considered as having been made on the date of its confirmation.

3. An express acceptance of, or an objection to, a reservation made previously to confirmation of the reservation does not itself require confirmation.

4. The withdrawal of a reservation or of an objection to a reservation must be formulated in writing.

• a proliferation of reservations in multilateral treaties can very well defeat the purpose of a treaty.
• bilateral treaties ー a reservation by one party means a rejection of the treaty and necessitates re-negotiation. 
• reservations are meant only for multilateral treaties

Q: Must a reservation be consented to by all parties for it to be effective? 

• Reservations to the Genocide Convention (ICJ Reports 1951), by seven votes to five:
• “A state which has made and maintained a reservation which has been objected to by one or more parties to the Convention but not by others, can be regarded as a party to the Convention if the reservation is compatible with the object and purpose of the Convention.” 
• “Compatibility could be decided by states individually since if a party to the Convention objects to a reservation which it considers incompatible with the object and purpose of the Convention, it can consider that the reserving state is not a party to the Convention.”
• It is possible for different legal relationships to arise among parties to the same treaty, as reflected in Article 19, of the Vienna Convention.

The Philippines and the 1982 Convention on the Law of the Sea

• In this connection, it should be noted that the provision on “archipelagic waters” found in the 1982 Convention on the Law of the Sea conflicts with the Philippine claim in Article I of the Constitution that the waters connecting the islands, irrespective of their breadth and dimension, are “internal waters.” 
• The Philippine government is clearly aware of these possible conflicts. 
• Hence, upon its ratification of the Convention on the Law of the Sea on August 5, 1984, it added the following reservation:

1. The signing of the Convention by the Government of the Republic of the Philippines shall not in any manner impair or prejudice the sovereign rights of the Republic of the Philippines under and arising from the Constitution of the Philippines;

2. Such signing shall not in any manner affect the sovereign rights of the Republic of the Philippines as successor to the United States of America, under and arising out of the Treaty of Paris between Spain and the United States of America of December 10, 1988, and the Treaty of Washington between the United States of America and Great Britain of January 2,1930;

3. Such signing shall not diminish or in any manner affect the rights and obligations of the Contracting Parties under the Mutual Defense Treaty between the Philippines and the United States of America of August 30,1951, and its related interpretative instruments; nor those under any pertinent bilateral or multilateral treaty or agreement to which the Philippines is a party.

6. The provisions of the Convention on archipelagic passage through sea lanes do not nullify or impair the sovereignty of the Philippines as an archipelagic State over the sea lanes and do not deprive it of authority to enact legislation to protect its sovereignty, independence, and security; 

7. The concept of archipelagic waters is similar to the concept of internal waters under the Constitution of the Philippines, and removes straits connecting these waters with the economic zone or high sea from the rights of foreign vessels to transit passage for international navigation; 

• The USSR filed a formal protest against the Philippine reservation. 
• However, the reservation does not seem to be necessary because Article 8(2) itself says that the new rule applies only to “areas which had not previously been considered as” internal waters. 
• The 1973 Constitution, which in its Article I classified as internal waters what is now referred to as archipelagic waters, pre-dates the 1982 Convention.

Reservations in Human Rights Treaties 

The Human Rights Committee of the UN made the following observations regarding reservations in human rights treaties: 

17. As indicated above, it is the Vienna Convention on the Law of Treaties that provides the definition of reservations and also the application of the object and purpose test in the absence of other specific provisions. But the Committee believes that its provisions on the role of State objections in relation to reservations are inappropriate to address the problem of reservations to human rights treaties. 

Such treaties, and the Covenant specifically, are not a web of inter-State exchanges of mutual obligations. They concern the endowment of individuals with rights. The principle of inter-State reciprocity has no place, save perhaps in the limited context of reservations to declarations on the Committee’s competence under Article 41. And because the operation of the classic rules on reservations is so inadequate for the Covenant, States have often not seen any legal interest in or need to object to reservations. The absence of protest by States cannot imply that a reservation is either compatible or incompatible with the object and purpose of the Covenant. Objections have been occasional, made by some States but not others, and on grounds not always specified; when an objection is made, it often does not specify a legal consequence, or sometimes even indicates that the objecting party nonetheless does not regard the Covenant as not in effect as between the parties concerned. In short, the pattern is so unclear that it is not safe to assume that a non-objecting State thinks that a particular reservation is acceptable. 

In the view of the Committee, because of the special characteristics of the Covenant as a human rights treaty, it is open to question what effect objections have between States inter se. However, an objection to a reservation made by States may provide some guidance to the Committee in its interpretation as to its compatibility with the object and purpose of the Covenant.

4. Entry into force of treaties 

• treaties enter into force on the date agreed upon by the parties
• where no date is indicated, the treaty enters into force once consent has been given
• multilateral treaties generally contain a provision which says how many states have to accept the treaty before it can come into force
• the rules on entry into force are as follows: 

Article 24. Entry into force: 

1. A treaty enters into force in such manner and upon such date as it may provide or as the negotiating States may agree. 

2. Failing any such provision or agreement, a treaty enters into force as soon as consent to be bound by the treaty has been established for all the negotiating States. 

3. When the consent of a State to be bound by a treaty is established on a date after the treaty has come into force, the treaty enters into force for that State on that date, unless the treaty otherwise provides. 

4. The provisions of a treaty regulating the authentication of its text, the establishment of the consent of States to be bound by the treaty, the manner or date of its entry into force, reservations, the functions of the depositary and other matters arising necessarily before the entry into force of the treaty apply from the time of the adoption of its text. 

Article 25. Provisional application: 

1. A treaty or a part of a treaty is applied provisionally pending its entry into force if: 

        (a) the treaty itself so provides; or

        (b) the negotiating States have in some other manner so agreed. 

2. Unless the treaty otherwise provides or the negotiating States have otherwise agreed, the provisional application of a treaty or a part of a treaty with respect to a State shall be terminated if that State notifies the other States between which the treaty is being applied provisionally of its intention not to become a party to the treaty.

Application of treaties

• the first fundamental rule on treaties is pacta sunt servanda. 

Article 26 of the Convention:
“every treaty in force is binding upon the parties to it
 and must be performed by them in good faith.”

• a second fundamental rule:

Article 46: 

“a party may not invoke 

the provisions of its internal law 

as justification for its failure 

to perform a treaty.”

• as to the territorial scope of its applicability:

Article 29: 

“Unless a different intention appears from the treaty 

or is otherwise established, 

a treaty is binding upon each party in respect of its entire territory.”

Interpretation of treaties

Article 31:

1. A treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given tot he terms of the treaty in their context and in the light of its object and purpose.

2. The context for the purpose of the interpretation of a treaty shall comprise, in addition to the text, including its preamble and annexes:

        (a) any agreement relating to the treaty which was made between all the parties in connection with the conclusion of the treaty; 

        (b) any instrument which was made by one or more parties in connection with the conclusion of the treaty and accepted by the other parties as an instrument related to the treaty.

3. There shall be taken into account, together with the context:

        (a) any subsequent agreement between the parties regarding the interpretation of the treaty or the application of its provisions;

        (b) any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation;

        (c) any relevant rules of international law applicable in the relations between the parties.

4. A special meaning shall be given to a term if it is established that the parties so intended.

• Article 31 combines various approaches to treaty interpretation. 
• Article 31(1) 一 “objective” approach, interpretation according to the ordinary meaning of the words
• Article 31(2) 一 “teleological” approach, interpretation according to the telos or purpose of the treaty
• Article 31(3) and (4) 一 “subjective” approach, which honors special meaning given by the parties
• where there are ambiguities in the meaning of a treaty, resort may be made to supplementary sources, Articles 32 and 33 are relevant:

Article 32. Supplementary means of interpretation. 

Recourse may be had to supplementary means of interpretation, including the preparatory work of the treaty and the circumstances of its conclusion, in order to confirm the meaning resulting from the application of Article 31, or to determine the meaning when the interpretation according to Article 31: 

           (a) leaves the meaning ambiguous or obscure; or 

        (b) leads to a result which is manifestly absurd or unreasonable. 

Article 33. Interpretation of treaties authenticated in two or more languages: 

1. When a treaty has been authenticated in two or more languages, the text is equally authoritative in each language, unless the treaty provides or the parties agree that, in case of divergence, a particular text shall prevail. 

2. A version of the treaty in a language other than one of those in which the text was authenticated shall be considered an authentic text only if the treaty so provides or the parties so agree.

3. The terms of the treaty are presumed to have the same meaning in each authentic text. 

4. Except where a particular text prevails in accordance with paragraph 1, when a comparison of the authentic texts discloses a difference of meaning which the application of Articles 31 and 32 does not remove, the meaning which best reconciles the texts, having regard to the object and purpose of the treaty, shall be adopted. 

• in case there is conflict among “official texts,” the language that is agreed by the parties as authoritative is followed.

AIR FRANCE V. SAKS 470 US 392

• (Syllabus) Article 17 of the Warsaw Convention makes air carriers liable for injuries sustained by a passenger “if the accident which caused the damage so sustained took place on board the aircraft or in the course of any of the operations of embarking or disembarking.” 
• Respondent, while a passenger on petitioner’s jetliner as it descended to land in Los Angeles on a trip from Paris, felt severe pressure and pain in her left ear, and the pain continued after the jetliner landed. Shortly thereafter, respondent consulted a doctor who concluded that she had become permanently deaf in her left ear. 
• She then filed suit in a California state court, alleging that her hearing loss was caused by negligent maintenance and operation of the jetliner’s pressurization system. 
• After the case was removed to Federal District Court, petitioner moved for summary judgment on the ground that respondent could not prove that her injury was caused by an “accident” within the meaning of Article 17, the evidence indicating that the pressurization system had operated in a normal manner. 
• Relying on precedent that defines the term “accident” in Article 17 as an “unusual or unexpected” happening, the District Court granted summary judgment to petitioner. 
• The Court of Appeals reversed, holding that the language, history, and policy of the Warsaw Convention and the Montreal Agreement (a private agreement among airlines that has been approved by the Federal Government) impose absolute liability on airlines for injuries proximately caused by the risks inherent in air travel; and that normal cabin pressure changes qualify as an “accident” within the definition contained in Annex 13 to the Convention on International Civil Aviation as meaning “an occurrence associated with the operation of an aircraft.”
• Held: Liability under Article 17 arises only if a passenger’s injury is caused by an unexpected or unusual event or happening that is external to the passenger, and not where the injury results from the passenger’s own internal reaction to the usual, normal, and expected operation of the aircraft, in which case it has not been caused by an accident under Article 17.
• (a) The text of the Warsaw Convention suggests that the passenger’s injury must be so caused. The difference in the language of Article 17 imposing liability for injuries to passengers caused by an “accident” and Article 18 imposing liability for destruction or loss of baggage by an “occurrence,” implies that the drafters of the Convention understood the word “accident” to mean something different than the word “occurrence.” Moreover, Article 17 refers to an accident which caused the passenger’s injury, and not to an accident which is the passenger’s injury. The text thus implies that, however “accident” is defined, it is the cause of the injury that must satisfy the definition rather than the occurrence of the injury alone. And, since the Warsaw Convention was drafted in French by continental jurists, further guidance is furnished by the French legal meaning of “accident” — when used to describe a cause of injury, rather than the event of injury — as being a fortuitous, unexpected, unusual, or unintended event. 
• (b) The above interpretation of Article 17 is consistent with the negotiating history of the Warsaw Convention, the conduct of the parties thereto, and the weight of precedent in foreign and American courts. 
• (c) While any standard requiring courts to distinguish causes that are “accidents” from causes that are “occurrences” requires drawing a line that may be subject to differences as to where it should fall, an injured passenger is only required to prove that some link in the chain of causes was an unusual or unexpected event external to the passenger. Enforcement of Article 17’s “accident” requirement cannot be circumvented by reference to the Montreal Agreement. That Agreement while requiring airlines to waive “due care” defenses under Article 20(1) of the Warsaw Convention, did not waive Article 17’s “accident” requirement. Nor can enforcement of Article 17 be escaped by reference to the equation of “accident” with “occurrence” in Annex 13, which, with its corresponding Convention, expressly applies to aircraft accident investigations and not to principles of liability to passengers under the Warsaw Convention.

Invalidity of Treaties. 

• the usual ground for invalidation of contracts can also invalidate a treaty: 
• error of fact
• fraud
• corruption
• duress (coercion)
• violation of jus cogens

Article 48. Error: 

1. A State may invoke an error in a treaty as invalidating its consent to be bound by the treaty if the error relates to a fact or situation which was assumed by that 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. 

2. Paragraph 1 shall not apply if the State in question 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. 

3. An error relating only to the wording of the text of a treaty does not affect its validity; Article 79 then applies. 

Article 49. Fraud: 

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

Article 50. Corruption of a representative of a State: 

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 the treaty. 

Article 51. Coercion of a representative of a State: 

The expression of a State’s consent to be bound by a treaty which has been procured by the coercion of its representative through acts or threats directed against him shall be without any legal effect. 

Article 52. Coercion of a State by the threat or use of force: 

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. 

Article 53. Treaties conflicting with a peremptory norm of general international law (jus cogens):

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

• the definition quoted here is based on the legal effect of the rule and not on its intrinsic nature 
• it seems to say that the rule is jus cogens because no derogation from it is permitted
• however, what jus cogens really means is that no derogation is allowed because it is jus cogens
• it is the intrinsic nature of the rule that disallows derogation

Q: What are the rules considered to be jus cogens? 

While there is wide acceptance of the existence of jus cogens, there is wide dispute as to what principles rank as jus cogens.

1966 Report of the International Law Commission: 

(a) a treaty contemplating an unlawful use of force contrary to the provisions of the Charter; 

(b) a treaty contemplating the performance of any other act criminal under international law; 

(c) a treaty contemplating or conniving towards the commission of acts such as trade in slaves, piracy, or genocide. 

But the Commission decided not to stipulate a list of jus cogens rules for fear of being misunderstood and for fear of prolonged debate. 

• a state, however, can lose the right to assert the invalidity of a treaty:

Article 45. Loss of a right to invoke a ground for invalidating, terminating, withdrawing from or suspending the operation of a treaty: 

A State may no longer invoke a ground for invalidating, terminating, withdrawing from or suspending the operation of a treaty under Articles 46 to 50 or Articles 60 and 62 if, after becoming aware of the facts:

        (a) it shall have expressly agreed that the treaty is valid or remains in force or continues in operation, as the case may be; or

        (b) it must by reason of its conduct be considered as having acquiesced in the validity of the treaty or in its maintenance in force or in operation, as the case may be. 

• a state, moreover, with limited exception, may not plead its municipal law as a ground for invalidating a treaty that has been entered

Article 46. Provisions of internal law regarding competence to conclude treaties: 

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

2. 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. 

Article 47. Specific restrictions on authority to express the consent of a State: 

If the authority of a representative to express the consent of a State to be bound by a particular treaty has been made subject to a specific restriction, his omission to observe that restriction may not be invoked as invalidating the consent expressed by him unless the restriction was notified to the other negotiating States prior to his expressing such consent. 

• Article 47 is an example of manifest violation.

Amendment and Modification of Treaties.

• a distinction is made between amendment and modification of a treaty. 
• amendment is a formal revision done with the participation, at least in its initial stage, by all the parties to the treaty
• modification involves only some of the parties. 
• the general rule on amendments, found in Article 39, is that:
•  “a treaty may be amended by agreement of the parties.” 
• the procedure that is followed is the same as that for the formation of treaties. 
• the process is simple enough with regard to bilateral treaties
• in recognition of the fact that it is not easy to obtain the consent of all in multilateral treaties, Article 40 provides for the possibility of amendments which will affect only some states but only after all parties have been given the opportunity to consider the proposed amendments
• Article 41, for its part, allows for modification of a treaty by two or more of the parties

Amendment 

Article 40. Amendment of multilateral treaties: 

1. Unless the treaty otherwise provides, the amendment of multilateral treaties shall be governed by the following paragraphs. 

2. Any proposal to amend a multilateral treaty as between all the parties must be notified to all the contracting States, each one of which shall have the right to take part in:

        (a) the decision as to the action to be taken in regard to such proposal; 

        (b) the negotiation and conclusion of any agreement for the amendment of the treaty. 

3. Every State entitled to become a party to the treaty shall also be entitled to become a party to the treaty as amended. 

4. The amending agreement does not bind any State already a party to the treaty which does not become a party to the amending agreement; Article 30, paragraph 4(b), applies in relation to such State. 

5. Any State which becomes a party to the treaty after the entry into force of the amending agreement shall, failing an expression of a different intention by that State: 

        (a) be considered as a party to the treaty as amended; and 

        (b) be considered as a party to the unamended treaty in relation to any party to the treaty not bound by the amending agreement.

Modification 

Article 41. Agreements to modify multilateral treaties between certain of the parties only — 

1. Two or more of the parties to a multilateral treaty may conclude an agreement to modify the treaty as between themselves alone if: 

        (a) the possibility of such a modification is provided for by the treaty ; or

        (b) the modification in question is not prohibited by the treaty and: 

                (i) does not affect the enjoyment by the other parties of their rights under the treaty or the performance of their obligations; 

                (ii) does not relate to a provision, derogation from which is incompatible with the effective execution of the object and purpose of the treaty as a whole. 

2. Unless in a case falling under paragraph 1(a) the treaty otherwise provides, the parties in question shall notify the other parties of their intention to conclude the agreement and of the modification to the treaty for which it provides.

Termination of Treaties.

• a treaty may be terminated or suspended according to the terms of the treaty or with the consent of the parties. 
• a treaty with a definite period may also expire
• it may also end when the purpose for the treaty has already been achieved. 
• but a mere change of government or severance of diplomatic relations does not terminate or suspend a treaty. 
• three other important modes of terminating a treaty are:
• material breach, 
• impossibility of performance and 
• change of fundamental conditions (rebus sic stantibus)

Material breach

Article 60. Termination or suspension of the operation of a treaty as a consequence of its breach: 

1. A material breach of a bilateral treaty by one of the parties entitles the other to invoke the breach as a ground for terminating the treaty or suspending its operation in whole or in part. 

2. A material breach of a multilateral treaty by one of the parties entitles:

        (a) the other parties by unanimous agreement to suspend the operation of the treaty in whole or in part or to terminate it either: 

                (i) in the relations between themselves and the defaulting State, or 

                (ii) as between all the parties; 

        (b) a party specially affected by the breach to invoke it as a ground for suspending the operation of the treaty in whole or in part in the relations between itself and the defaulting State; 

        (c) any party other than the defaulting State to invoke the breach as a ground for suspending the operation of the treaty in whole or in part with respect to itself if the treaty is of such a character that a material breach of its provisions by one party radically changes the position of every party with respect to the further performance of its obligations under the treaty. 

3. A material breach of a treaty, for the purposes of this article, consists in: 

        (a) a repudiation of the treaty not sanctioned by the present Convention; or 

        (b) the violation of a provision essential to the accomplishment of the object or purpose of the treaty. 

4. The foregoing paragraphs are without prejudice to any provision in the treaty applicable in the event of a breach. 

5. Paragraphs 1 to 3 do not apply to provisions relating to the protection of the human person contained in treaties of a humanitarian character, in particular to provisions prohibiting any form of reprisals against persons protected by such treaties.

Supervening impossibility of performance

Article 61. Supervening impossibility of performance: 

1. A party may invoke the impossibility of performing a treaty as a ground for terminating or withdrawing from it if the impossibility results from the permanent disappearance or destruction of an object indispensable for the execution of the treaty. If the impossibility is temporary, it may be invoked only as a ground for suspending the operation of the treaty.

 

2. Impossibility of performance may not be invoked by a party as a ground for terminating, withdrawing from or suspending the operation of a treaty if the impossibility is the result of a breach by that party either of an obligation under the treaty or of any other international obligation owed to any other party to the treaty.

Rebus sic stantibus 

Article 62. Fundamental change of circumstances: 

1. A fundamental change of circumstances which has occurred with regard to those existing at the time of the conclusion of a treaty, and which was not foreseen by the parties, may not be invoked as a ground for terminating or withdrawing from the treaty unless: 

        (a) the existence of those circumstances constituted an essential basis of the consent of the parties to be bound by the treaty; and 

        (b) the effect of the change is radically to transform the extent of obligations still to be performed under the treaty. 

2. A fundamental change of circumstances may not be invoked as a ground for terminating or withdrawing from a treaty: 

        (a) if the treaty establishes a boundary; or 

        (b) if the fundamental change is the result of a breach by the party invoking it either of an obligation under the treaty or of any other international obligation owed to any other party to the treaty.

3. If, under the foregoing paragraphs, a party may invoke a fundamental change of circumstances as a ground for terminating or withdrawing from a treaty it may also invoke the change as a ground for suspending the operation of the treaty. 

• Article 62 is a codification of the common law principle of rebus sic stantibus. 
• but the modern approach to it is restrictive.
• Fisheries Jurisdiction case (ICJ Reports 1973):
• international law admits that a fundamental change in the circumstances which determined the parties to accept a treaty, if it has resulted in a radical transformation of the extent of the obligations imposed by it, may, under certain conditions, afford the party affected a ground for invoking the termination or suspension of the treaty.
• the changes “must have increased the burden of the obligations to be executed to the extent of rendering performance something essentially different from the original intention.”

FISHERIES JURISDICTION CASE (UNITED KINGDOM V. ICELAND) ICJ REP 1973 3

• The United Kingdom, as part of what was known as “the Cod Wars,” applied to the Court claiming that the proposed extension of Iceland’s exclusive fisheries jurisdiction from 12 miles to SO miles was a breach of an agreement between the two states, evidenced by an Exchange of Notes in 1961. 
• Iceland contended that the Court had no jurisdiction to hear the case and it also submitted that any agreement which it had with the United Kingdom not to extend its fisheries jurisdiction, was no longer binding due to a fundamental change of circumstances since that agreement.
• The court decided that it did have jurisdiction. It also considered that Art. 62 of the Vienna Convention on the Law of Treaties represented customary international law.
• One of the basic requirements embodied [Article 62] is that the change of circumstances must have been a fundamental one. In this respect the Government of Iceland has, with regard to developments in fishing techniques, referred ... to the increased exploitation of the fishery resources in the seas surrounding Iceland and to the danger of still further exploitation because of an increase in the catching capacity of fishing fleets. The Icelandic statements recall the exceptional dependence of that country on its fishing for its existence and economic development.” 
• The invocation by Iceland of its ‘ vital interests ’, which were not made the subject of an express reservation to the acceptance of the jurisdictional obligation under the 1961 Exchange of Notes, must be interpreted, in the context of the assertion of changed circumstances, as an indication by Iceland of the reason why it regards as fundamental the changes which in its view have taken place in previously existing fishing techniques. This interpretation would correspond to the traditional view that the changes of circumstances which must be regarded as fundamental or vital are those which imperil the existence or vital development of one of the parties.
• Moreover, in order that a change of circumstances may give rise to a ground for invoking the termination of a treaty it is also necessary that it should have resulted in a radical transformation of the extent of the obligations still to be performed. The change must have increased the burden of the obligations to be executed to the extent of rendering the performance something essentially different from the originally undertaken. In respect of the obligation with which the Court is here concerned, this condition is wholly unsatisfied; the change of circumstances alleged by Iceland cannot be said to have transformed radically the extent of the jurisdictional obligation which is imposed in the 1961 Exchange of Notes. The compromissory clause enabled either of the parties to submit to the Court any dispute between them relating to an extension of Icelandic fisheries jurisdiction in the waters above its continental shelf beyond the 12- mile limit. The present dispute is exactly of the character anticipated in the compromissory clause of the Exchange of Notes. Not only has the jurisdictional obligation not been radically transformed in its extent; it has remained precisely what it was in 1961.

NAMIBIA CASE ICJ REP 1971 16 

• The Security Council had resolved that South Africa’s Mandate over South-West Africa (Namibia) was terminated, but this had been ignored by South Africa. 
• The Security Council then resolved, by Resolution 276 (1970), that the continued presence of South Africa in Namibia was illegal. It sought an advisory opinion from the Court, asking what were the legal consequences for States of the continued presence of South Africa in Namibia notwithstanding Resolution 276 (1970). 
• The Court held that South Africa was under an obligation to withdraw its administration in Namibia. It also held that other States where under an obligation not to recognize any acts by South Africa’s administration in Namibia (see Chapter 5).
• In examining this action of the General Assembly, it is appropriate to have regard to the general principles of international law regulating termination of a treaty relationship on account of breach. For even if the mandate is viewed as having the character of an institution, as is maintained, it depends on those international agreements which created the system and regulated its application. As the Court indicated in 1962 ‘this Mandate, like practically all other similar Mandates’ was a special type of instrument composite in nature and instituting a novel international regime. It incorporates a definite agreement. (ICJ Rep 1962, p. 331). The Court stated conclusively in that Judgment that the Mandate ... ‘in fact and in law, is an international agreement having the character of a treaty or convention.’ (ICJ Rep 1962, p. 330). The rules laid down by the Vienna Convention on the Law of Treaties concerning termination of a treaty relationship on account of breach (adopted without a dissenting vote) may in many respects be considered as a codification of existing customary law on the subject. In the light of these rules, only a material breach of a treaty justifies termination, such breach being defined as: (a) a repudiation of the treaty not sanctioned by the present Convention; or (b) the violation of a provision essential to the accomplishment of the object or purpose of the treaty. (Art. 60, para. 3)
• General Assembly Resolution 2145 (XXI) determines that both forms of material breach had occurred in this case. By stressing that South Africa ‘has, in fact, disavowed the Mandate’, the General Assembly declared in fact that it had repudiated it. The resolution in question is therefore to be viewed as the exercise of the right to terminate a relationship in case of a deliberate and persistent violation of obligations which destroys the very object and purpose of that relationship.
• It has been contended that the Covenant of the League of Nations did not confer on the Council of the League power to terminate a mandate for misconduct of the mandatory and that no such power could therefore be exercised by the United Nations, since it could not derive from the League greater powers than the latter itself had. For this objection to prevail it would be necessary to show that the mandates system, as established under the League, excluded the application of the general principle of law that a right of termination on account of breach must be presumed to exist in respect of all treaties, except as regards provisions relating to the protection of the human person contained in treaties of a humanitarian character (as indicated in Art. 60, para. 5, of the Vienna Convention). The silence of a treaty as to the existence of such a right cannot be interpreted as implying the exclusion of a right which has its source outside the treaty, in general international law, and is dependent on the occurrence of circumstances which are not normally envisaged when a treaty is concluded.
• It has been suggested that, even if the Council of the League had possessed the power of revocation of the Mandate in an extreme case, it could not have been exercised unilaterally but only in co-operation with the Mandatory which had committed a serious breach of the obligations it had undertaken. To contend, on the basis of the principle of unanimity which applied in the League of Nations, that in this case revocation could only take place with the concurrence of the Mandatory, would not only run contrary to the general principle of law governing termination on account of breach, but also postulate an impossibility. For obvious reasons, the consent of the wrongdoers to such a form of termination cannot be required.

DANUBE DAM CASE (Hungary v. Slovakia) 37ILM162 (1998) 

• In 1977, Hungary and Czechoslovakia concluded a treaty to facilitate the construction of dams on the Danube River. Hungary later suspended works due to environmental concerns in response to which Czechoslovakia carried out unilateral measures. 
• Hungary then claimed the right to terminate the treaty, at which point the dispute was submitted to the International Court of Justice. Hungary also submitted that it was entitled to terminate the Treaty on the ground that Czechoslovakia had violated Articles of the Treaty by undertaking unilateral measures, culminating in the diversion of the Danube. 
• Slovakia became a party to the 1977 Treaty as successor to Czechoslovakia (see above on succession)
• The 1977 Treaty does not contain any provision regarding its termination.. 
• The Court will now turn to the first ground advanced by Hungary, that of the state of necessity. In this respect, the Court will merely observe that, even if a state of necessity is found to exist, it is not a ground for the termination of a treaty. It may only be invoked to exonerate from its responsibility a State which has failed to implement a treaty.
• Hungary also relied on the principle of the impossibility of performance as reflected in Article 61 ... [I]f the joint exploitation of the investment was no longer possible, this was originally because Hungary did not carry out most of the works for which it was responsible; Article 61, paragraph 2, of the Vienna Convention expressly provides that impossibility of performance may not be invoked for the termination of a treaty by a party to that treaty when it results from that party’s own breach of an obligation flowing from that treaty.
• Hungary further argued that it was entitled to invoke a number of events which, cumulatively, would have constituted a fundamental change of circumstances [changes of political nature, the reduced economic viability of the Project, and the progress of environmental knowledge and international environmental law]. The changed circumstances advanced by Hungary are, in the Court’s view, not of such a nature’ that their effect would radically transform the extent of the obligations still to be performed in order to accomplish the Project. A fundamental change of circumstances must have been unforeseen; the existence of the circumstances must have constituted an essential basis of the consent of the parties to be bound by the treaty.
•  It is only a material breach of the treaty itself, by a State party to that treaty, which entitles the other party to rely on it as a ground for terminating the treaty. The violation of other treaty rules or of rules of general international law may justify the taking of certain measures, including countermeasures, by the injured State, but it does not constitute a ground for termination under the law of treaties.
• Czechoslovakia violated the Treaty only when it diverted the waters of the Danube into the bypass canal in October 1992. In constructing the works which would lead to the putting into operation of [the unilateral measure], Czechoslovakia did not act unlawfully. 
• In the Court’s view, therefore, the notification of termination by Hungary on 19 May 1992 was premature.

Procedure for the Termination of Treaties 

Article 65. Procedure to be followed with respect to invalidity, termination, withdrawal from or suspension of the operation of a treaty — 

1. A party which, under the provisions of the present Convention, invokes either a defect in its consent to be bound by a treaty or a ground for impeaching the validity of a treaty, terminating it, withdrawing from it or suspending its operation, must notify the other parties of its claim. The notification shall indicate the measure proposed to be taken with respect to the treaty and the reasons therefor. 

2. If, after the expiry of a period which, except in cases of special urgency, shall not be less than three months after the receipt of the notification, no party has raised any objection, the party making the notification may carry out in the manner provided in Article 67 the measure which it has proposed. 

3. If, however, objection has been raised by any other party, the parties shall seek a solution through the means indicated in Article 33 of the Charter of the United Nations. 

4. Nothing in the foregoing paragraphs shall affect the rights or obligations of the parties under any provisions in force binding the parties with regard to the settlement of disputes. 

5. Without prejudice to Article 45, the fact that a State has not previously made the notification prescribed in paragraph 1 shall not prevent it from making such notification in answer to another party claiming performance of the treaty or alleging its violation. 

Article 66. Procedures for judicial settlement, arbitration and conciliation: 

If, under paragraph 3 of Article 65, no solution has been reached within a period of 12 months following the date on which the objection was raised, the following procedures shall be followed: 

        (a) any one of the parties to a dispute concerning the application or the interpretation of Article 53 or 64 may, by a written application, submit it to the International Court of Justice for a decision unless the parties by common consent agree to submit the dispute to arbitration;

        (b) any one of the parties to a dispute concerning the application or the interpretation of any of the other articles in Part V of the present Convention may set in motion the procedure specified in the Annex to the Convention by submitting a request to that effect to the Secretary-General of the United Nations.

Article 67. Instruments for declaring invalid, terminating, withdrawing from or suspending the operation of a treaty — 

1. The notification provided for under Article 65, paragraph 1 must be made in writing. 

2. Any act declaring invalid, terminating, withdrawing from or suspending the operation of a treaty pursuant to the provisions of the treaty or of paragraphs 2 or 3 of Article 65 shall be carried out through an instrument communicated to the other parties. If the instrument is not signed by the Head of State, Head of Government or Minister for Foreign Affairs, the representative of the State communicating it may be called upon to produce full powers. 

Article 68. Revocation of notifications and instruments provided for in Articles 65 and 67: 

A notification or instrument provided for in Article 65 or 67 may be revoked at any time before it takes effect.

Authority to Terminate 

• while the Vienna Convention enumerates those who have the capacity to enter into treaties, it does not say who may terminate a treaty.
• however, the authority to terminate should also belong to the one who has the authority to enter into the treaty. 
• in the Philippines, however, as in the United States, the authority to conclude treaties is shared between the Senate and the President.'

Q: Can the President unilaterally terminate a treaty? 

Goldwater v. Carter, discussed this question relative to President Carter’s termination of the defense treaty with Taiwan. No decision was reached except to say that the matter was not yet ripe for judicial review: 

“The Judicial Branch should not decide issues affecting the allocation of power between the President and Congress until the political branches reach a constitutional impasse. Otherwise, we would encourage small groups or even individual Members of Congress to seek judicial resolution of issues before the normal political process has the opportunity to resolve the conflict.”

Succession to treaties. 

Q: When one state ceases to exist and is succeeded by another on the same territory, is the new state is bound by the commitments made by its predecessor?
1978 Vienna Convention on the Succession of States with Respect to Treaties (November 6, 1996):

The Convention follows the “clean slate” rule. 

Article 16 says: 

“A newly independent State is not bound to maintain in force, or to become a party to, any treaty by reason only of the fact that at the date of the succession of States the treaty was in force in respect of the territory to which the succession of States relates.” 

• but a new state may agree to be bound by the treaties made by its predecessor.
• the “clean slate” rule, however, does not apply to treaties affecting boundary regimes

Article 11. Boundary regimes 

A succession of States does not as such affect: 

        (a) a boundary established by a treaty ; or 

        (b) obligations and rights established by a treaty and relating to the regime of a boundary. 

Article 12. Other territorial regimes 

1. A succession of States does not as such affect: 

        (a) obligations relating to the use of any territory, or to restrictions upon its use, established by a treaty for the benefit of any territory of a foreign State and considered as attaching to the territories in question; 

        (b) rights established by a treaty for the benefit of any territory and relating to the use, or to restrictions upon the use, of any territory of a foreign State and considered as attaching to the territories in question. 

2. A succession of States does not as such affect: 

        (a) obligations relating to the use of any territory, or to restrictions upon its use, established by a treaty for the benefit of a group of States or of all States and considered as attaching to that territory; 

        (b) rights established by a treaty for the benefit of a group of States or of all States and relating to the use of any territory, or to restrictions upon its use, and considered as attaching to that territory. 

3. The provisions of the present article do not apply to treaty obligations of the predecessor State providing for the establishment of foreign military bases on the territory to which the succession of States relates.