This section outlines what happens to a treaty after it is adopted. The time line below shows a possible sequence of events as a treaty enters into force and States become parties to it.
(See the Summary of Practice, paras. 221-247.)
Typically, the provisions of a multilateral treaty determine the date upon which the treaty enters into force. Where a treaty does not specify a date or provide another method for its entry into force, the treaty is presumed to be intended to come into force as soon as all negotiating States have consented to be bound by the treaty.
Treaties, in general, may enter into force:
See, e.g., article VIII of the Protocol relating to the Status of Refugees, 1967:
The present Protocol shall come into force on the day of deposit of the sixth instrument of accession.
See, e.g., article XIV of the Comprehensive Nuclear-Test-Ban Treaty, 1996:
This Treaty shall enter into force 180 days after the date of deposit of the instruments of ratification by all States listed in Annex 2 to this Treaty, but in no case earlier than two years after its opening for signature.
See, e.g., article 126(1) of the Rome Statute of the International Criminal Court, 1998:
This Statute shall enter into force on the first day of the month after the 60th day following the date of the deposit of the 60th instrument of ratification, acceptance, approval or accession with the Secretary-General of the United Nations.
See, e.g., article 45(1) of the International Coffee Agreement 2001, 2000:
This Agreement shall enter into force definitively on 1 October 2001 if by that date Governments representing at least 15 exporting Members holding at least 70 percent of the votes of the exporting Members and at least 10 importing Members holding at least 70 percent of the votes of the importing Members, calculated as at 25 September 2001, without reference to possible suspension under the terms of Articles 25 and 42, have deposited instruments of ratification, acceptance or approval. ...
Once a treaty has entered into force, if the number of parties subsequently falls below the minimum number specified for entry into force, the treaty remains in force unless the treaty itself provides otherwise (see article 55 of the Vienna Convention 1969).
Where a State definitively signs or ratifies, accepts, approves or accedes to a treaty that has already entered into force, the treaty enters into force for that State according to the relevant provisions of the treaty. Treaties often provide for entry into force for a State in these circumstances:
See, e.g., article 126(2) of the Rome Statute of the International Criminal Court, 1998:
For each State ratifying, accepting, approving or acceding to this Statute after the deposit of the 60th instrument of ratification, acceptance, approval or accession, the Statute shall enter into force on the first day of the month after the 60th day following the deposit by such State of its instrument of ratification, acceptance, approval or accession.
See, e.g., article VIII of the Protocol relating to the Status of Refugees, 1967:
For each State acceding to the Protocol after the deposit of the sixth instrument of accession, the Protocol shall come into force on the date of deposit by such State of its instrument of accession.
It is noted, nevertheless, that some treaties include provisions for their provisional entry into force. This enables States that are ready to implement the obligations under a treaty to do so among themselves, without waiting for the minimum number of ratifications necessary for its formal entry into force, if this number is not obtained within a given period. See, e.g., the International Coffee Agreement, 1994, as extended until 30 September 2001, with modifications, by Resolution No. 384 adopted by the International Coffee Council in London on 21 July 1999, 1994. Once a treaty has entered into force provisionally, it creates obligations for the parties that agreed to bring it into force in that manner.
Many treaties contain detailed dispute resolution provisions, but some contain only elementary provisions. Where a dispute, controversy or claim arises out of a treaty (for example, due to breach, error, fraud, performance issues, etc.) these provisions become extremely important. If a treaty does not provide a dispute resolution mechanism, article 66 of the Vienna Convention 1969 may apply.
Treaties may provide various dispute resolution mechanisms, such as negotiation, consultation, conciliation, use of good offices, panel procedures, arbitration, judicial settlement, reference to the International Court of Justice, etc. See, e.g., article 119(2) of the Rome Statute of the International Criminal Court, 1998:
Any other dispute between two or more States Parties relating to the interpretation or application of this Statute which is not settled through negotiations within three months of their commencement shall be referred to the Assembly of States Parties. The Assembly may itself seek to settle the dispute or may make recommendations on further means of settlement of the dispute, including referral to the International Court of Justice in conformity with the Statute of that Court.
In some recently concluded treaties, detailed compliance mechanisms are included. Many disarmament treaties and some environmental treaties provide compliance mechanisms, for example, by imposing monitoring and reporting requirements. See, e.g., article 8 of the Montreal Protocol on Substances that Deplete the Ozone Layer, 1987, which provides that the parties "... shall consider and approve procedures and institutional mechanisms for determining non-compliance with the provisions of this Protocol and for treatment of Parties found to be in non-compliance". During the Fourth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (Copenhagen 1992), the parties adopted a detailed non-compliance procedure (Report of the Fourth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer, 1992 (UNEP/OzL.Pro.4/15), decision IV/5, and annexes IV and V; see UNEP Ozone Secretariat's web site).
Many human rights treaties provide for independent committees to oversee the implementation of their provisions. For example, the Convention on the Elimination of All Forms of Discrimination against Women, 1979; the Optional Protocol to the Convention on the Elimination of All Forms of Discrimination against Women, 1999; and the International Covenant on Civil and Political Rights, 1966.
(See the Summary of Practice, paras. 248-255.)
The text of a treaty may be amended in accordance with the amendment provisions in the treaty itself or in accordance with chapter IV of the Vienna Convention 1969. If the treaty does not specify any amendment procedures, the parties may negotiate a new treaty or agreement amending the existing treaty.
An amendment procedure within a treaty may contain provisions governing the following:
See, e.g., article 12(1) of the Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict, 2000:
Any State Party may propose an amendment and file it with the Secretary-General of the United Nations. The Secretary-General shall thereupon communicate the proposed amendment to States Parties with a request that they indicate whether they favour a conference of States Parties for the purpose of considering and voting upon the proposal. ...
Normally, the relevant treaty secretariat circulates proposals of amendment. The treaty secretariat is in the best position to determine the validity of the amendment proposed and undertake any necessary consultation. The treaty itself may detail the secretariat's role in this regard. In the absence of circulation of the amendment by the treaty body, the Secretary-General, as depositary, may perform this function.
Amendments may be adopted by States parties at a conference or by an executive body such as the executive arm of the treaty. See, e.g., article 13(4) of the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, 1997:
Any amendment to this Convention shall be adopted by a majority of two-thirds of the States Parties present and voting at the Amendment Conference. The Depositary shall communicate any amendment so adopted to the States Parties.
Treaties normally specify that a party must formally consent to be bound by an amendment, following adoption, by depositing an instrument of ratification, acceptance or approval of the amendment. See, e.g., article 39(3) of the United Nations Convention against Transnational Organized Crime, 2000:
An amendment adopted in accordance with paragraph 1 of this article is subject to ratification, acceptance or approval by States Parties.
An amendment can enter into force in a number of ways, e.g., upon:
Adoption of the amendment;
Elapse of a specified time period (30 days, three months, etc.);
Its assumed acceptance by consensus if, within a certain period of time following its circulation, none of the parties to the treaty objects; or
Deposit of a specified number of instruments of ratification, acceptance or approval, etc.
See, e.g., article 20(4) of the Kyoto Protocol to the United Nations Framework Convention on Climate Change, 1997:
Instruments of acceptance in respect of an amendment shall be deposited with the Depositary. An amendment adopted in accordance with paragraph 3 above shall enter into force for those Parties having accepted it on the ninetieth day after the date of receipt by the Depositary of an instrument of acceptance by at least three fourths of the Parties to this Protocol.
Depending on the treaty provisions, an amendment to a treaty may, upon its entry into force, bind:
Only those States that formally accepted the amendment (see paragraph (d) above); or
In rare cases, all States parties to the treaty.
Where a State becomes party to a treaty which has undergone amendment, it becomes party to the treaty as amended, unless otherwise indicated (see article 40(5)(a) of the Vienna Convention 1969). The provisions of the treaty determine which States are bound by the amendment. See, e.g., article 13(5) of the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, 1997:
An amendment to this Convention shall enter into force for all States Parties to this Convention, which have accepted it, upon the deposit with the Depositary of instruments of acceptance by a majority of States Parties. Thereafter it shall enter into force for any remaining State Party on the date of deposit of its instrument of acceptance.
Where a treaty has not entered into force, it is not possible to amend the treaty pursuant to its own provisions. Where States agree that the text of a treaty needs to be revised, subsequent to the treaty's adoption, but prior to its entry into force, signatories and contracting parties may meet to adopt additional agreements or protocols to address the problem. While contracting parties and signatories play an essential role in such negotiations, it is not unusual for all interested countries to participate. See, e.g., the Agreement relating to the implementation of Part XI of the United Nations Convention on the Law of the Sea of 10 December 1982, 1994.
The Secretary-General, as depositary, is guided by the amendment provisions of a treaty in determining when an amendment to the treaty enters into force. Many treaties specify that an amendment enters into force when a specified number of ratifications, acceptances or approvals are received by the depositary. However, where the amendment provision specifies that entry into force occurs when a certain proportion of the parties to a treaty have ratified, accepted or approved the amendment, then the determination of the time of entry into force becomes less certain. For example, if an amendment is to enter into force after two-thirds of the parties have expressed their consent to be bound by it, does this mean two-thirds of the parties to the treaty at the time the amendment is adopted or two-thirds of the parties to the treaty at any given point in time following such adoption?
In these cases, it is the Secretary-General's practice to apply the latter approach, sometimes called the current time approach. Under this approach, the Secretary-General, as depositary, counts all parties at any given time in determining the time an amendment enters into force. Accordingly, States that become parties to a treaty after the adoption of an amendment but before its entry into force are also counted. As far back as 1973, the Secretary-General, as depositary, applied the current time approach to the amendment of Article 61 of the Charter of the United Nations.
(See the Summary of Practice, paras. 157-160.)
In general terms, a party may withdraw from or denounce a treaty:
In accordance with any provisions of the treaty enabling withdrawal or denunciation (see article 54(a) of the Vienna Convention 1969);
With the consent of all parties after consultation with all contracting States (see article 54(b) of the Vienna Convention 1969); or
In the case of a treaty that is silent on withdrawal or denunciation, by giving at least 12 months' notice, and provided that:
It is established that the parties intended to admit the possibility of denunciation or withdrawal; or
A right of denunciation or withdrawal may be implied by the nature of the treaty (see article 56 of the Vienna Convention 1969).
States wishing to invoke article 56 of the Vienna Convention 1969 ((c)(i) and (ii) above) carry the burden of proof.
Some treaties, including human rights treaties, do not contain withdrawal provisions. See, e.g., the International Covenant on Civil and Political Rights, 1966. The Secretary-General, as depositary, has taken the view that it would not appear possible for a party to withdraw from such a treaty except in accordance with article 54 or 56 of the Vienna Convention 1969 (see depositary notification C.N.467.1997.TREATIES-10).
Where a treaty contains provisions on withdrawal, the Secretary-General is guided by those provisions. For example, article 12(1) of the Optional Protocol to the International Covenant on Civil and Political Rights, 1966, provides for denunciation by States parties as follows:
Any State Party may denounce the present Protocol at any time by written notification addressed to the Secretary-General of the United Nations. Denunciation shall take effect three months after the date of receipt of the notification by the Secretary-General.
This provision has been used by a State to notify the Secretary-General of its intention to denounce the Protocol.
(See the Summary of Practice, paras. 256-262.)
Treaties may include a provision regarding their termination. Article 42(2) of the Vienna Convention 1969 states that a treaty may only be terminated as a result of the application of the provisions of the treaty itself or of the Vienna Convention 1969 (e.g., articles 54, 56, 59-62 and 64). A treaty can be terminated by a subsequent treaty to which all the parties of the former treaty are also party.