Reservations to Treaties

Held, by seven votes to five.

On the first question. A State which has made and maintained a reservation objected to by one or more parties to the Convention but not by others can be regarded as a party if the reservation is compatible with the object and purpose of the Convention, and otherwise cannot.

On the second question. A party which objects to a reservation it considers incompatible with the object and purpose may in fact consider the reserving State not to be a party, and a party which accepts the reservation as compatible may in fact consider it to be a party.

On the third question. An objection by a signatory which has not yet ratified has the effect indicated only upon ratification, and until then serves merely as notice of that State's eventual attitude. An objection by a State entitled to sign or accede but which has not done so is without legal effect.

The reasoning, which is where the marks are. In the absence of any article providing for reservations, one cannot infer that they are prohibited. Whether a reservation is permissible must be answered from the character, purpose, provisions and mode of preparation of the particular convention. The principles underlying the Genocide Convention are recognised by civilised nations as binding on States even without any conventional obligation. Its purpose is purely humanitarian and civilising, and the contracting States have no individual advantages or interests of their own but merely a common interest, so that as many States as possible should participate. That purpose would be defeated if an objection to a minor reservation produced complete exclusion. Equally, the parties could not have intended to sacrifice the very object of the Convention to a vague desire for numbers.

What the opinion did. It replaced unanimity with compatibility with the object and purpose, and it left the assessment to each State individually, which is the flexible, and the criticised, half of the system. The Vienna Convention generalised the test in 1969 to every multilateral treaty.

When a reservation may be made: article 19

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 one in question, may be made; or

(c) in cases not falling under (a) and (b), the reservation is incompatible with the object and purpose of the treaty.

So the presumption is freedom, and the three exceptions are cumulative in the order given. Subparagraph (c) is the Genocide opinion in statutory form.

Acceptance and objection: article 20

Article 20(1). A reservation expressly authorised by the treaty requires no subsequent acceptance by the other contracting States, unless the treaty so provides.

Article 20(2), the surviving unanimity rule. When it appears from the limited number of the negotiating States and the object and purpose of the 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, a reservation requires acceptance by all the parties. The old rule therefore survives for small closed treaties, where it was always sensible.

Article 20(3), constituent instruments. When a treaty is the constituent instrument of an international organisation, and unless it otherwise provides, a reservation requires the acceptance of the competent organ of that organisation. The organisation, not the individual States, decides.

Article 20(4), the general regime. In cases not falling under the preceding paragraphs, and unless the treaty otherwise provides:

(a) Acceptance by another contracting State constitutes the reserving State a party in relation to that other State, if or when the treaty is in force for them.

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

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

Article 20(5), tacit acceptance. A reservation is considered accepted by a State if it has raised no objection by the end of twelve months after being notified of it, or by the date on which it expressed its consent to be bound, whichever is later.

Read 20(4)(b) carefully. The default of an objection is that the treaty still enters into force between the two States. To keep the reserving State out altogether, the objecting State must definitely express that intention. An ordinary objection is therefore what is called a simple objection, and the rare one is the objection with maximum effect.

The effect of a reservation: article 21

Article 21(1). A reservation established in accordance with articles 19, 20 and 23 modifies for the reserving State, in its relations with the accepting party, the provisions to which it relates to the extent of the reservation, and modifies those provisions to the same extent for that other party in its relations with the reserving State.

Reciprocity is the point. If State AA reserves against an article, State BB may equally decline to apply that article to State AA. The reserving State gains no one-way advantage.

Article 21(2). The reservation does not modify the provisions for the other parties inter se. The treaty runs unmodified between everyone else.

Article 21(3), the simple objection. Where an objecting State 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.

Set 21(1) and 21(3) beside each other and a curiosity appears: acceptance and simple objection often produce nearly the same result, because either way the reserved provisions do not operate between the two States to the extent of the reservation. The practical difference between accepting and objecting is therefore smaller than students expect, and lies mainly in what the objection records for the future.

Withdrawal and procedure: articles 22 and 23

Article 22(1). Unless the treaty otherwise provides, a reservation may be withdrawn at any time, and the consent of a State which has accepted it is not required.

Article 22(2). An objection may likewise be withdrawn at any time.

Article 22(3). Withdrawal of a reservation becomes operative in relation to another contracting State only when notice is received by that State, and withdrawal of an objection only when notice is received by the reserving State.

Article 23(1). A reservation, an express acceptance and an objection must be formulated in writing and communicated to the contracting States and other States entitled to become parties.

Article 23(2), the confirmation rule. A reservation formulated when signing subject to ratification, acceptance or approval must be formally confirmed when the State expresses its consent to be bound, and is then considered as having been made on the date of confirmation.

Article 23(3). An acceptance or objection made before that confirmation does not itself require confirmation.

Article 23(4). Withdrawal of a reservation or of an objection must be in writing.

Human rights treaties: the standing difficulty

The 1951 opinion concerned a humanitarian convention in which States had no individual advantages, only a common interest. That reasoning cuts both ways in modern human rights treaties.

The problem of reciprocity. Article 21 works by reciprocity, and reciprocity is close to meaningless where the obligation is owed to individuals rather than to other States. A State that reserves against a right does not gain something the other State can withhold in return.

The problem of the decider. Under articles 19 and 20 each State judges compatibility for itself. Where a treaty establishes a supervisory body, the question arises whether that body may decide instead, and whether an incompatible reservation is void while the ratification stands, so that the State is bound without the benefit of its reservation. That position, called severability, is asserted by several treaty bodies and resisted by several States. The Vienna Convention does not answer it, and an answer that says so, and states both positions, is a better answer than one that picks a side without argument.

A worked example

The Convention on ZZ has 60 parties and no article on reservations. State AA accedes with a reservation excluding the compulsory dispute settlement article. State BB accepts. State CC objects, saying nothing more. State DD objects and states that in consequence the Convention shall not enter into force between itself and State AA. State EE, a signatory that has not ratified, objects. State FF says nothing for two years.

Is the reservation permissible? The treaty neither prohibits reservations nor lists permitted ones, so article 19(c) applies and the test is compatibility with the object and purpose. A reservation to a dispute settlement clause is generally regarded as compatible, since it goes to enforcement machinery and not to the substantive obligations, though the answer depends on the character and purpose of the particular convention, exactly as the Court said in 1951.

State AA and State BB. Article 20(4)(a) makes State AA a party in relation to State BB, and article 21(1) means the dispute settlement article does not operate between them, in both directions.

State AA and State CC. Article 20(4)(b): the objection does not prevent the treaty entering into force between them, because no contrary intention was definitely expressed. Article 21(3): the reserved provisions do not apply between them to the extent of the reservation. The result is practically the same as with State BB.

State AA and State DD. State DD definitely expressed the contrary intention, so the Convention does not enter into force between them at all.

State EE's objection. It has effect only upon ratification, and until then is notice of State EE's eventual attitude. That is the answer to the third question in the 1951 opinion.

State FF's silence. Article 20(5): a reservation is considered accepted if no objection is raised within twelve months of notification, or by the date of consent to be bound, whichever is later. State FF has accepted by silence.

Change one fact: State AA withdraws the reservation. Article 22(1) allows withdrawal at any time without the consent of those who accepted, and article 22(3)(a) makes it operative against each State only when that State receives notice.

Distinctions table

What it does NOT mean

The label does not decide. Article 2(1)(d) applies however phrased or named.

A reservation cannot be made after becoming a party. It belongs to the act of expressing consent, subject to confirmation under article 23(2).

An objection does not usually keep the reserving State out. Article 20(4)(b) requires the contrary intention to be definitely expressed.

A reservation does not change the treaty for everyone. Article 21(2) confines it to the reserving State's relations with the party concerned.

Unanimity is not dead. It survives in article 20(2) for treaties among a limited number of States where entire application is essential.

The 1951 opinion was not unanimous. It was seven votes to five, and a candidate who says the Court was unanimous has misstated the record.

Limits and criticism

Each State judges compatibility for itself, which is the flexibility the 1951 opinion chose and the incoherence it produced. The same reservation may be compatible for one party and incompatible for another, so the treaty means different things around the table.

Article 19(c) has no enforcement machinery. The Convention says a reservation must not be incompatible with the object and purpose, and then says nothing about who decides or what follows if it is.

Reciprocity does not fit human rights or environmental treaties, where obligations are not owed State to State, so article 21 provides no real discipline on the reserving State.

Vague and general reservations, such as those subjecting a treaty to a State's domestic law as a whole, are widely made, seldom effectively objected to, and difficult to reconcile with the requirement that a reservation relate to certain provisions.

Quick revision

Definition, article 2(1)(d): a unilateral statement, however phrased or named, made when signing, ratifying, accepting, approving or acceding, purporting to exclude or modify the legal effect of certain provisions in their application to that State.

Genocide Reservations, ICJ Reports 1951, p. 15, 7 votes to 5: a reserving State is a party if the reservation is compatible with the object and purpose; each objecting or accepting State judges for itself; an objection by a non-ratifying signatory takes effect only on ratification; by a State that has not signed or acceded, none. Replaced the rule of unanimity.

Article 19: reservations permitted unless (a) prohibited, (b) not among those specified, or (c) incompatible with object and purpose.

Article 20: (1) expressly authorised needs no acceptance; (2) unanimity survives for limited-number treaties needing entire application; (3) constituent instruments need the competent organ; (4)(b) objection does not prevent entry into force unless definitely expressed; (5) silence for twelve months is acceptance.

Article 21: reciprocal modification between reserving and accepting State; no effect for the others inter se; on simple objection the reserved provisions do not apply between the two.

Article 22: withdrawal at any time, effective on receipt of notice. Article 23: in writing; a reservation made on signature must be confirmed on consent to be bound.

Test yourself

1. Define a reservation and distinguish it from an interpretative declaration.

By article 2(1)(d) a reservation is 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 in their application to that State. An interpretative declaration states what the declaring State understands a provision to mean without excluding or modifying its effect. Because article 2(1)(d) applies however phrased or named, the distinction is one of substance: if the statement in truth excludes or modifies legal effect it is a reservation and articles 19 to 23 govern it, whatever the State chose to call it.

2. State the facts, the questions and the holding in the Genocide Reservations opinion.

The Genocide Convention contained no article on reservations, and by a resolution of 16 November 1950 the General Assembly asked the Court three questions: whether a State making a reservation objected to by some parties but not others could be regarded as a party, what the effect of such a reservation was between the reserving State and the objecting and the accepting parties, and what the legal effect was of an objection by a signatory that had not ratified or by a State that had not signed or acceded. The Court advised, by seven votes to five, that such a State can be regarded as a party if the reservation is compatible with the object and purpose of the Convention and otherwise cannot; that a party which considers the reservation incompatible may in fact consider the reserving State not to be a party, while a party which accepts it may consider it to be one; and that an objection by a non-ratifying signatory takes effect only upon ratification while an objection by a State entitled to sign or accede that has not done so is without legal effect.

3. Why did the Court reject both unanimity and complete freedom?

Because of the character and purpose of the Convention. Its principles are recognised by civilised nations as binding on States even without any conventional obligation, its purpose is purely humanitarian and civilising, and the contracting States have no individual advantages or interests of their own but merely a common interest, so that as many States as possible should participate. Unanimity would defeat that purpose by excluding a State altogether because of an objection to a minor reservation. Complete freedom would sacrifice the very object of the Convention to a vague desire for numbers. The compatibility test with object and purpose was the middle course, and the Vienna Convention generalised it in article 19(c).

4. When is a reservation impermissible under article 19?

In three cases. Where the reservation is prohibited by the treaty. Where the treaty provides that only specified reservations may be made and the reservation in question is not among them. And, in cases not falling under those two, where the reservation is incompatible with the object and purpose of the treaty. Outside those three cases a State is free to formulate a reservation when signing, ratifying, accepting, approving or acceding, which means freedom is the rule and prohibition the exception.

5. State AA objects to State BB's reservation but says nothing about entry into force. What follows?

By article 20(4)(b) the objection does not preclude the entry into force of the treaty as between the objecting and reserving States, because a contrary intention was not definitely expressed. By article 21(3), since State AA has not opposed entry into force, the provisions to which the reservation relates do not apply as between the two States to the extent of the reservation. The practical outcome is therefore close to what acceptance under article 21(1) would have produced, and the difference lies chiefly in the position State AA has placed on record.

6. What is the special difficulty about reservations to human rights treaties?

Two difficulties. The Vienna Convention's machinery works by reciprocity, since article 21 modifies the treaty equally in both directions between the reserving and the accepting State, and reciprocity is close to meaningless where the obligation is owed to individuals rather than to other States, so a reserving State loses nothing by reserving. And articles 19 and 20 leave each State to judge compatibility for itself, which raises the unresolved question whether a treaty's supervisory body may decide instead, and whether an incompatible reservation is severable, so that the State remains bound without the benefit of its reservation. Several treaty bodies assert that position and several States reject it, and the Vienna Convention does not settle it.