International Law Commission International Law Commission

Last update: August 25, 2015

Analytical Guide to the Work of the International Law Commission

Law of treaties

See also: Summary | Texts and Instruments

Mandate

1949 Decision of the International Law Commission to award priority to the topic following its survey of the whole field of international law with a view to selecting topics for codification, in pursuance of article 18 of its Statute.

Studies undertaken by the Secretariat and Reports of the Secretary-General

  • 2nd session of the International Law Commission (1950)
    • Bibliography on the Law of Treaties — prepared by the Secretariat
  • 7th session of the International Law Commission (1955)
    • Working paper prepared by the Secretariat
  • 11th session of the International Law Commission (1959)
    • Practice of the United Nations Secretariat in relation to certain questions raised in connexion with the articles on the law of treaties
  • 15th session of the International Law Commission (1963)
    • Resolutions of the General Assembly concerning the law of treaties: memorandum prepared by the Secretariat
  • 17th session of the International Law Commission (1965)
    • Depositary practice in relation to reservations: Report by the Secretary-General submitted in accordance with General Assembly resolution 1452 B (XIV)
  • 18th session of the International Law Commission (1966)
    • Preparation of Multilingual Treaties: memorandum by the Secretariat

Reports of the Working Group or Sub-Committee

None

Reports of the Special Rapporteur

  • Proposed draft Convention on the Law of Treaties, together with an explanatory note by the Special Rapporteur, and commentaries.
    • Report of the Special Rapporteur, James L. Brierly (2nd session of the ILC (1950)
  • Several draft articles on the conclusion of treaties (art.1), entry into force of treaties (art.2), application of treaties (art.3), ratification of treaties (art.4), when ratification is necessary (art.5), date of entry into force of treaties (art.6), obligation of a signatory prior to the entry into force of a treaty (art.7), no obligation to ratify (art.8), accession to treaties (art.9), together with commentaries.
    • Report of the Special Rapporteur, James L. Brierly (3rd session of the ILC (1951))
  • Articles tentatively adopted by the Commission at its third session with commentaries thereon: capacity to make treaties (art.1), competence of Head of State (art.2), establishment of the text of treaties (art.3), assumption of treaty obligations (art.4), ratification of treaties (art.5), when ratification is necessary (art.6), no obligation to ratify (art.7), entry into force of treaties (art.8), accession to treaties (art.9), acceptance (art.10).
    • Report of the Special Rapporteur, James L. Brierly (4th session of the ILC (1952))
  • Text of articles with commentaries divided into the following parts: definition and nature of treaties (part I), conclusion of treaties (part II), Conditions of validity of treaties (part III). Part III is subdivided into the following sections: capacity of the parties and their agents (sec.I), reality of consent (sec.II), legality of the object of the treaty (sec.III), and form and publicity (sec.IV).
    • Report of the Special Rapporteur, Sir Hersch Lauterpacht (5th session of the ILC (1953))
  • Further texts of revised articles 1 (essential requirements of a treaty), 6 (ratification), 7 (accession), 9 (reservations), and 16 (consistency with prior treaty obligation), with commentaries.
    • Report of the Special Rapporteur, Sir Hersch Lauterpacht (6th session of the ILC (1954))
  • Set of draft articles concentrating on the topic of the framing and conclusion of treaties as well as a section devoted to certain basic principles of treaty law, with commentaries.
    • Report of the Special Rapporteur, Sir Gerald Fitzmaurice (8th session of the ILC (1956))
  • Part III of the proposed first chapter of the envisaged code on treaty law, dealing with temporal validity (duration, termination, revision and modification of treaties), with commentaries.
    • Second Report of the Special Rapporteur, Sir Gerald Fitzmaurice (9th session of the ILC (1957))
  • Part II of the proposed first chapter of the envisaged code on treaty law, dealing with essential validity (intrinsic legality and operative force of treaties), with commentaries.
    • Third Report of the Special Rapporteur, Sir Gerald Fitzmaurice, (10th session of the ILC (1958))
  • Turned to the proposed second chapter (the effects of treaties), and considered part I, vol. Iz. The effects of treaties as between the parties (operation, execution and enforcement), with commentaries.
    • Fourth Report of the Special Rapporteur, Sir Gerald Fitzmaurice, (11th session of the ILC (1959))
  • Part II of the proposed second chapter (effects of treaties) on the effects of treaties in relation to third States with commentaries.
    • Fifth Report of the Special Rapporteur, Sir Gerald Fitzmaurice, (12th session of the ILC (1960))
  • Twenty-three draft articles on the conclusion, entry into force and registration of treaties together with commentaries.
    • First Report of the Special Rapporteur, Sir Humphrey Waldock, (14th session of the ILC (1962))
  • Part II (Arts. 30–54) of the draft articles on the essential validity, duration and termination of treaties.
    • Second Report of the Special Rapporteur, Sir Humphrey Waldock (15th session of the ILC (1963))
  • Part III (Arts. 55-) of the draft articles on the application, effects, revision and interpretation of treaties.
    • Third Report of the Special Rapporteur, Sir Humphrey Waldock (16th session of the ILC (1964))
  • Summary of comments of Governments and delegations on the twenty-nine articles of part I and first three articles of part II and proposals for the revision of the articles in the light of those comments.
    • Fourth Report of the Special Rapporteur, Sir Humphrey Waldock (First part of the 17th session of the ILC (1965))
  • Revision of Part II, sections 1–3 of the draft articles.
    • Fifth Report of the Special Rapporteur, Sir Humphrey Waldock (Second part of the 17th session of the ILC (1966))
  • Revision of Part II, section 4 and Part III of the draft articles.
    • Sixth Report of the Special Rapporteur, Sir Humphrey Waldock (18th session of the ILC (1966))

Reports of the Drafting Committee

None

Comments by Governments

  • 2nd session of the International Law Commission (1950)
    • Replies from Governments to Questionnaire of the International Law Commission, addressed to them under article 19(2) of its Statute
  • 17th session of the International Law Commission (1965)
    • Comments by Governments on parts I, II and III of the Draft Articles on the Law of Treaties drawn up by the Commission at its fourteenth, fifteenth and sixteenth sessions
  • 18th session of the International Law Commission (1966)
    • Comments by Governments on parts I, II and III of the Draft Articles on the Law of Treaties drawn up by the Commission at its fourteenth, fifteenth and sixteenth sessions

Other

  • 3rd session of the International Law Commission (1951)
    • Text of articles tentatively adopted by the Commission at its third session
  • Redraft of articles suggested by the Special Rapporteur in the light of the discussions and decisions of the Commission
  • Text of articles tentatively adopted by the Commission at its 88th meeting, 24 May 1951
  • Draft article prepared by Dr. Yuen-li Yang at the request of Mr. J. L. Brierly, Special Rapporteur
  • Draft Convention on the Law of treaties contained in the first report of the Special Rapporteur
  • 5th session of the International Law Commission (1953)
    • Memorandum submitted by Mr. M. J. M. Yepes
  • 17th session of the International Law Commission (1965)
    • Addition to article 29 or new article 29 bis, proposed by Mr. S. Rosenne
  • 17th session of the International Law Commission (1965)
    • Draft articles adopted by the Commission
  • 18th session of the International Law Commission (1966)
    • Revised draft articles

Reports of the International Law Commission

  • Report of the International Law Commission on the work of its first session, 12 April to 19 June 1949
    • Appointed James L. Brierly as Special Rapporteur with a view to preparing a working paper for submission to the Commission at its second session.
    • Discussion in Plenary: 33rd meeting (3 June 1949)
  • Report of the International Law Commission on the work of its second session, 5 June to 29 July 1950
    • The Commission undertook its consideration of the topic on the basis of the report of the Special Rapporteur and the replies of Governments to a questionnaire addressed to them. It considered the scope of the subject to be covered in its study. Provisionally decided that exchange of notes should be covered. A majority favoured the inclusion in its study of agreements to which international organizations are parties. There existed a divergence of views on the effect of constitutional provisions as to the exercise of capacity to make treaties. The Commission also discussed the part of the report dealing with reservations. The Special Rapporteur was requested to continue his work in the light of the discussions and to submit further reports at the next session.
    • Discussion in plenary: 49th, 50th, 51st, 52nd and 53rd meetings (19 to 23 June 1950)
  • Report of the International Law Commission on the work of its third session, 16 May to 27 July 1951
    • The Commission considered the draft articles contained in the Special Rapporteur's second report as well as some others in his first report. Various amendments were adopted and tentative texts were provisionally agreed upon. These texts were referred to the Special Rapporteur who was requested to present to the Commission, at its fourth session, a final draft, together with a commentary thereon. The Special Rapporteur was also requested to do further work on the topic of the law of treaties as a whole and to submit a report thereon to the Commission.
    • Discussion in Plenary: 84th, 85th, 86th, 87th and 88th meetings (18 to 24 May 1951), and 98th, 99th, 100th,102nd, 103rd, 104th, 105th and 106th, meetings (7 to 19 June 1951)
  • Report of the International Law Commission on the work of its fourth session, 4 June to 8 August 1952
    • The Commission had before it the third report of the Special Rapporteur. However, owing to his resignation from membership in the Commission, it did not consider it expedient to discuss the report. Mr. H. Lauterpacht was elected Special Rapporteur on the law of treaties, to succeed Mr. Brierly, and was requested to present a report at its fifth session in 1953.
    • Discussion in Plenary: 178th and 179th meetings (1 to 4 August 1952)
  • Report of the International Law Commission on the work of its fifth session, 1 June to 14 August 1953
    • The Commission decided to request the Special Rapporteur, Mr. H. Lauterpacht, to continue his work on the subject and to present a further report for discussion at the next session together with the report held over from the present session.
    • Discussion in Plenary: 227th meeting (30 July 1953)
  • Report of the International Law Commission on the work of its sixth session, 3 June to 28 July 1954
    • The two reports on the law of treaties submitted by the Special Rapporteur, Mr. Hersch Lauterpacht, were held over for consideration at the next session.
  • Report of the International Law Commission on the work of its seventh session, 2 May to 8 July 1955
    • Following the resignation of Sir Hersch Lauterpacht, Sir Gerald Fitzmaurice was appointed Special Rapporteur on the Law of Treaties.
  • Report of the International Law Commission on the work of its eighth session, 23 April to 4 July 1956
    • Owing to a lack of time, the Commission was unable to enter upon a full discussion of the report. It did, however, consider certain general questions placed before it by the Special Rapporteur regarding the form and scope of the codification envisaged in this field. The Special Rapporteur was requested to continue his work in the light of the debate.
    • Discussion in plenary: 368th, 369th and 370th meetings (15 to 19 June 1956)
  • Report of the International Law Commission on the work of its ninth session, 23 April to 28 June 1957
    • Due to a lack of time, the Commission was unable to consider the second report of the Special Rapporteur.
  • Report of the International Law Commission on the work of its tenth session, 28 April to 4 July 1958
    • Due to a lack of time, the Commission was unable to consider the third report of the Special Rapporteur.
  • Report of the International Law Commission on the work of its eleventh session, 20 April to 26 June 1959
  • Report of the International Law Commission on the work of its twelfth session, 25 April to 1 July 1960
    • The Commission did not take up the topic during the session.
  • Report of the International Law Commission on the work of its thirteenth session, 1 May to 7 July 1961
    • Following the resignation of Sir Gerald Fitzmaurice, the Commission appointed Sir Humphrey Waldock as Special Rapporteur for the law of treaties. The Commission decided i) that its aim would be to prepare draft articles on the law of treaties intended to serve as the basis for a convention; ii) that the Special Rapporteur should be requested to re-examine the work previously done in this field by the Commission and its Special Rapporteurs; and iii) that the Special Rapporteur should begin with the question of the conclusion of treaties and then proceed with the remainder of the subject, if possible covering the whole subject in two years.
    • Discussion in plenary: 620th and 621st meetings (28 to 29 June 1961)

General Assembly Action

  • Resolution 1765 (XVII) of 20 November 1962
    • Recommended that the Commission continue the work on the law of treaties, taking into account the views expressed in the Assembly and the written comments submitted by Governments.
 

Final Outcome

International Law Commission (18th session, 1966)

  • Adopted draft articles at its 893rd meeting on 18 July 1966 and recommended the convening of an international conference of plenipotentiaries to study the Commission's draft articles and to conclude a convention on the subject.

General Assembly

  • Resolution 2166 (XXI) of 5 December 1966
    • Decided to convene an international conference of plenipotentiaries to consider the law of treaties and to embody the results of its work in an international convention and such other instruments as it may deem appropriate.
  • Resolution 2287(XXII) of 6 December 1967
    • Decided to convene the first session of the United Nations Conference on the Law of Treaties at Vienna in March 1968.1
  • Resolution 3233 (XXIX) of 12 November 1974
    • Decided to invite all States to become parties to the Vienna Convention on the Law of Treaties.
 

1 The Vienna Conference on the Law of Treaties was held from 26 March to 24 May 1968 and 9 April to 22 May 1969. The Vienna Convention on the Law of Treaties (United Nations Treaty Series, v1155, p.331) was adopted on 23 May 1969.