Tacit Consent/Opting Out Procedure
- International organizations, practice and procedure — Treaties, amendments and modification — Vienna Convention on the Law of Treaties — Treaties, conclusion — Treaties, entry into force — Sovereignty — State practice
Published under the auspices of the Max Planck Foundation for International Peace and the Rule of Law under the direction of Rüdiger Wolfrum.
1. Definition and Main Characteristics
1 There is no generally accepted definition of the term tacit consent/opting out procedure. Meanwhile this specific amendment procedure can be found in a large number of multilateral treaties in various different forms (Treaties, Amendment and Revision). The main characteristics of this procedure are the following: based on treaty provisions, an organ of an international organization or a particular treaty body (International Organizations or Institutions, Decision-Making Bodies), such as a technical committee or a commission of experts, usually adopts a regulation by majority vote (International Organizations or Institutions, Voting Rules and Procedures; see also International Organizations or Institutions, Decision-Making Process). This regulation does not need to be individually ratified, approved, or accepted by the States Parties to become legally binding. All States Parties are bound by it after the expiry of a certain time period, unless a State Party has explicitly objected to the regulation. This means that the acceptance of the States Parties bound by the regulation is deemed to be given by tacit consent, whereas a State Party that does not want to be legally bound has the opportunity to opt out by expressly notifying its objection within a certain time limit. A variation of this procedure would require anobjecting State to entirely withdraw from the treaty (Hollis 749).
2 This narrow notion of tacit consent combined with an opting out procedure should be distinguished from the general notion of expressing the ? consent to an act of international law-making in a tacit form. This broader notion is in principle accepted in international law for the conclusion of treaties (Treaties, Conclusion and Entry into Force), as well asfor their termination (Treaties, Termination) and the acceptance of reservations (Treaties, Multilateral, Reservations to), even though the validity of tacit consent will depend on the circumstances of the individual case. Furthermore, the narrow version of tacit consent/opting out, permitting a State to opt out with the result that only the objecting State remains unbound, should be distinguished from a similar procedure where States will be bound by a proposed amendment unless at least one State lodged an objection. In this constellation, if one Stateor a threshold number of States opposes the amendment, it is rejected. Such a procedure has been included in the United Nations Convention on the Law of the Sea in its Art.313, as well asin Art.XV Maritime Labour Convention.
3 According to Art. 39 in connection with Arts 11 and 24 Vienna Convention on the Law of Treaties (1969) (‘VCLT’), amendments to a multilateral treaty traditionally need the consent of all or, if so agreed, at least a qualified majority of States Parties (see also Consensus). As a rule, a treaty or an amendment only becomes effective for those States that have explicitly accepted it. The classical methods of expressing consent to be bound are ratification, acceptance, approval, or accession. These methods proved to be extremely time-consuming, and often led to the result that amendments did not enter into force at all. This was particularly unsatisfactory with regard to subject-matters which had to be adapted to technological or scientific changes. Therefore, in State practice a specific accelerated amendment procedure based on tacit consent was developed that made the timely adaptation of predominantly technical provisions possible. The price that had to be paid for this advantage was the concession that States Parties not willing to be bound could avoid the legally binding effect by opting out. In short, the tacit consent/opting out procedure is usually characterized as a simplified procedure for amending international treaties or protocols and, in particular, their annexes or appendices. The first multilateral treaty that provided for a tacit consent/opting out procedure was the Chicago Convention (1944) establishing the International Civil Aviation Organization (ICAO). After World War II this procedure made its way into numerous international conventions (see also History of International Law, since World War II), mainly dealing with modern traffic (Traffic and Transport, International Regulation) and communication, scientific matters and environmental protection (Environment, International Protection). It has now become a common mode of international standard-setting.
B. Scope of Application
4 Early examples for the tacit consent/opting out procedure as a law-making method can be found within some United Nations (UN) Specialized Agencies (United Nations, Specialized Agencies; see also International Law Development through International Organizations, Policies and Practice). In addition, it is used by various treaty bodies, which have been vested with legislative competence in the respective international treaties. It has become common practice to separate basic treaty provisions from regulations or standards of a technical, scientific, or administrative nature. These are often contained in annexes or appendices to the treaty. Whereas for the amendment of the treaty itself or its protocols explicit consent is required (see also Framework Agreements), annexes and appendices can usually be amended by a tacit consent/opting out procedure. This simplified amendment procedure is frequently used in international environmental law and in treaties for the conservation of living resources (Conservation of Natural Resources; Environment, Multilateral Agreements), and more generally, if the provisions address more technical or scientific matters or administrative details, respectively (Hollis 748).
1. United Nations Specialized Agencies
(a) International Civil Aviation Organization and World Health Organization
5 As already mentioned, the ICAO was the first international organization that could adopt technical regulations, incorporating them into annexes to the convention on the basis of the tacit consent/opting out procedure. The Council of the ICAO, which is composed of the representatives of 36 Member States, has the competence to adopt international aviation standards by a two-thirds majority vote (Arts 54 (1) and 90 (a) Chicago Convention). In order to give non-members of the Council influence on the law-making process, such international standard shall not become effective if within three months after its adoption a majority of States Parties register their objection (Art. 90 (a) Chicago Convention). The mentioned provision is an example of a prohibitive quorum, whereby a majority of Member States can prevent the entry into force of international standards. It is a mechanism to safeguard the sovereignty of the States Parties to the Chicago Convention. In practice, however, the rejection of an aviation standard has never occurred, because in its preparatory stage it is thoroughly discussed by all Member States. After a standard has become effective, any State Party which finds it impracticable to comply with such standard (Compliance) has the possibility to opt out by immediately notifying the ICAO of the differences in relation to its own practice (Art. 38 Chicago Convention).
6 Another early example of the tacit consent/opting out procedure can be found in the Constitution of the World Health Organization (WHO). According to Art. 22 WHO Constitution, health and other regulations which have been adopted by the World Health Assembly (‘Assembly’) by a majority vote shall become legally binding for all members after due notice of their adoption, except for such members that have notified a rejection or reservation within the specific time period stated in the notice. There is no provision allowing for a rejection by a majority of members as provided for in Art. 90 (a) Chicago Convention. As far as reservations to regulations are concerned, they have to be accepted by the Assembly. If the Assembly objects to them on the ground that they are not in conformity with the object and purpose of the regulations (Treaties, Object and Purpose), these will not enter into force with respect to the State that made the inadmissible reservation until it has been withdrawn (Art. 107 International Sanitary Regulations, Art. 88 International Health Regulations). Most of the reservations which have been rejected by the Assembly have been withdrawn with the consequence that the States concerned are bound by the regulations in their entirety.
(b) World Meteorological Organization and International Telecommunication Union
7 A similar law-making mechanism can be found in the World Meteorological Organization (WMO), where Member States have the possibility of avoiding the legally binding effect of technical standards adopted by the WMO Congress, the plenary representative body, by a two-thirds majority vote (Art. 8 (d) in connection with Art. 11 (b) WMO Convention). If ‘any Member finds it impracticable to give effect to some requirements in a technical resolution… [it] shall inform the Secretary-General whether its inability to give effect to it is provisional or final, and state its reasons therefor’ (Art. 9 (b) WMO Convention). Although the language of this provision is vague, the WMO practice has shown that the Member States understand it as providing for a tacit consent/opting out procedure (see also Interpretation in International Law).
8 Within the framework of the International Telecommunication Union (ITU) the tacit consent/opting out procedure is part of a complex law-making process. It is only applicable in the case of revision of the two Administrative Regulations that complement the ITU Constitution and Convention. In general, any revision of the Administrative Regulations enters into force only for Member States that have notified their consent to be bound (Art. 54 (2bis) ITU Constitution). A revision applies provisionally in respect of any Member State that has signed, but not yet ratified it. The provisional application does not take effect if the Member State in question opposes it at the time of signature (Art. 54 (3 penter) ITU Constitution). If a Member State fails to notify its consent to be bound within 36 months after the revision's entry into force, that Member State shall be deemed to have consented to be bound by that revision (Art. 54 (5 bis) ITU Constitution). This means that for a Member State which has signed the revision and has then remained inactive, this revision becomes provisionally applicable after signature (Treaties, Provisional Application) and finally legally binding 36 months after its entry into force.
(c) International Maritime Organization
9 Under the auspices of the International Maritime Organization (IMO), more than 60 international conventions and protocols or amendments thereto have been adopted. In contrast to the international organizations mentioned above, the IMO Convention itself does not provide for a tacit consent/opting out procedure. This is due to the fact that the International Maritime Consultative Organization (‘IMCO’, the name was changed to IMO in 1982) had only limited competences. Its functions were mainly consultative and advisory. The introduction of a facilitated amendment procedure into most of the conventions adopted by IMO was a reaction to the fact that the ratification process with regard to amendments was so slow that some of them never entered into force. One prominent example is several amendments to the 1960 International Convention on the Safety of Life at Sea (‘SOLAS’; Maritime Safety Regulations), which had to be ratified by two-thirds of the contracting parties but never met this requirement. In 1969, a working group established by the IMO Council examined the amendment procedures of ICAO, ITU, WHO, and WMO, which showed that these organizations were able to update technical and other standards within a reasonable time period. The Legal Committee recommended that the tacit acceptance procedure should apply only to the technical parts of conventions mostly contained in annexes and appendices, whereas the non-technical provisions should continue to require explicit acceptance. IM(C)O established draft models which contained guidelines for future treaties.
10 Since 1972, the tacit consent/opting out procedure has been incorporated into most of IMO's technical conventions. Although the tacit acceptance procedures in the various conventions differ slightly from each other, they have some common features. The amendments must usually be adopted by either the Maritime Safety Committee (‘MSC’), the Marine Environment Protection Committee (‘MEPC’; Marine Environment, International Protection), or the Conference of the Parties (‘COP’ Conference [Meeting] of States Parties) by a two-thirds majority. They are deemed to be accepted at the end of a set period of time, unless a specified number of contracting parties, usually at least one third, has objected. If this prohibitive quorum has not been reached, the amendment enters into force for all contracting parties after a certain time period, with the exception of those parties which, before that date, have notified their objection. The tacit consent/opting out procedure has been extremely successful in the context of IMO conventions. Its incorporation into the majority of IMO conventions greatly strengthened IMO's ability effectively and expediently to adapt safety and environmental standards to new technological developments and scientific progress.
(d) International Labour Organisation
11 The International Labour Organization(ILO) for the first time incorporated a procedure of tacit consent in the Maritime Labour Convention (‘MLC’).This treaty will enter into force in August 2013, one year after the accession of the 30th State, representing at least a share of 33% of world gross tonnage of ships (Art. VIII MLC).The MLC aims to summarize and develop the standards applicable for seafarers, and supersedes as between its parties a significant number of previous conventions (Art. X MLC). In order to continuously review the standards adopted by the Convention, a special committee of Member State representatives and representatives of shipowners and seafarers is established (Art. XIII MLC).The MLC is accompanied by ‘Regulations’ and a ‘Code’. Art. VIMLC defines that the Regulations are binding for States, thereby replacing the obligations from the superseded treaties. For these Regulations, Part A of the Code defines more detailed obligations, named ‘standards’, which also create binding legal obligations for the parties (Art. VI (1) MLC). In contrast, Part B of the Code comprises non-binding ‘guidelines’ to implement the binding obligations. In order to provide for an accelerated form of amending the Code, Art. XV MLC permits amendments to the Code by means of a tacit consent procedure: after amendments have been adopted by the MLC Committee by a majority vote (Art. XV (4) MLC), States have regularly two years to ‘formally express their disagreement’ (Art. XV (8) MLC), and are otherwise considered to be bound by the amendment. Whereas amendments to the articles of the Convention and to the Regulations requireunanimity, includingratification in accordance with Art. XIV MLC, the binding standards and non-binding guidelines are amendable by tacit consent. Nevertheless, the Code has to be developed within the framework of the Regulations, thus limiting the scope of this simplified procedure of modification. This dual technique was considered to be one of the most innovative parts of the Convention, in particular to facilitate the modification of the Convention’s more technical rules. It is thereby a typical example of a tacit consent/opting out procedure.
2. Environmental Law
12 In most environmental treaties, annexes or appendices are amended by means of a tacit consent/opting out procedure. Usually a treaty organ such as the COP or a commission/committee of experts adopts amendments by a majority vote. They become effective for all States Parties with the exception of such parties which have declared their objection within a certain period of time. A good example is the procedure of amending the Appendices to the 1973 Convention on International Trade in Endangered Species of Wild Fauna and Flora (‘CITES’; Endangered Species, International Protection). In order to protect certain species of animals or plants against over-exploitation by means of a permit system, the species are grouped in three appendices according to how threatened they are by international trade. Appendix I includes species threatened with extinction; trade in specimens of these species is, except in very limited circumstances, prohibited. Appendix II includes species which are not necessarily threatened with extinction, but in whose respect trade must be controlled. Appendix III contains a list of species included at the request of a party that already regulates trade in the species and that needs the co-operation of other countries to prevent unsustainable or illegal exploitation. Amendments to Appendices I and II to include, remove, or transfer certain species from one Appendix to the other have to be adopted by a two-thirds majority of parties present at the COP and voting. They enter into force for all parties 90 days after that meeting, except for those which make a reservation by notification in writing to the depositary government with respect to that amendment (Art. XV CITES). A reservation puts such party in a position equivalent to that of a non-party with which trade in the species concerned is permitted. Therefore, a reservation is in fact an objection to the amendment, namely a way of opting out from it. This simplified amendment procedure has far-reaching consequences for the national law of States Parties (International Law and Domestic [Municipal] Law). Since they are obliged to penalize the trade in specimens in violation of CITES (Art. VIII CITES), amendments to the Appendices are usually incorporated into national penal law without the participation of national parliaments. Thus, majority decisions adopted in a tacit consent/opting out procedure have a considerable effect on individual rights which gives rise to concerns regarding the legitimacy of treaty-based law-making.
13 Similar tacit consent/opting out procedures for the adoption and amendment of annexes are provided for in the Bonn Convention on the Conservation of Migratory Species of Wild Animals (‘Bonn Convention’; Arts X and XI), the 1985 Vienna Convention for the Protection of the Ozone Layer (Arts 9 and 10 ; Ozone Layer, International Protection), the 1989 Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal (Arts 17 and 18 ; Hazardous Substances, Transboundary Impacts), the 1992 Framework Convention on Climate Change (Arts 15 and 16 ; Climate, International Protection), and the 1992 Convention on Biological Diversity (Arts 29 and 30 ; Biological Diversity, International Protection). In contrast to the amendment provisions in CITES and the Bonn Convention, the other conventions mentioned above oblige the parties first to make every effort to reach consensus with respect to a proposed amendment. Only if all efforts towards a consensus have been exhausted, shall the amendment be adopted by a majority vote differing from two-thirds to three-quarters of the parties present and voting.
14 The 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, aiming at the reduction and eventual elimination of the consumption and production of certain ozone-depleting substances, contains an even more innovative regulatory technique. Adjustments to the ozone-depleting potentials and adjustments and reductions in levels of production and consumption of controlled substances are subject to a simplified decision-making procedure. Having failed consensus and as a last resort, such adjustments shall be adopted by two-thirds of the parties present and voting representing a majority of developing and developed States. Such adjustments introducing tightened controls on certain substances, ie chlorofluorocarbons and halons, and accelerating the phase-out schedules of such substances enter into force automatically six months after the date of official notification by the depositary. Unlike amendments to the Protocol, ie to add new substances, being subject to ratification, these adjustments are binding for all parties which do not even have the possibility to opt out (Art. 2 (9) (c) and (d)). Therefore, the Meeting of the Parties has legislative powers with regard to some of the core commitments of the protocol.
15 In contrast, the 1992 United Nations Economic Commission for Europe (‘ECE’) Convention on the Transboundary Effects of Industrial Accidents (‘1992 ECE Convention’) and the 1994 Protocol on Further Reduction of Sulphur Emissions (‘1994 Sulphur Reduction Protocol’) to the 1979 ECE Convention on Long-Range Transboundary Air Pollution (Air Pollution, Transboundary Aspects) contain strict requirements for the tacit consent/opting out procedure. Amendments have to be adopted either by consensus or, if consensus cannot be reached, by a nine-tenths majority vote. They become effective for those parties which have not notified an objection, provided that no more than 16 parties have submitted such a notification (Art. 26 (4) 1992 ECE Convention; Art. 11 (4) 1994 Sulphur Reduction Protocol). In this case, the requirement of a high degree of acceptance (a nine-tenths majority) has been combined with that of a positive quorum (at least 16 States Parties) which is needed to prevent the amendment from entering into force. An even more watered-down version of a tacit consent/opting out procedure can be found in the 1992 Convention on the Protection of the Marine Environment of the Baltic Sea (‘Baltic Sea Convention’; Baltic Sea). Annexes and amendments thereto have to be adopted in the Baltic Marine Environment Protection Commission by unanimous vote (Art. 19 (5) Baltic Sea Convention). They become effective after the expiry of a certain time period unless any one of the parties lodges an objection (Art. 32 (3) Baltic Sea Convention). This means that despite the requirement of unanimity with regard to the adoption of an annex or an amendment, each contracting party has a right of veto.
3. Conservation of Living Resources
16 Another field of application for the tacit consent/opting out procedure is fisheries agreements. An early example can be found in the 1946 International Convention for the Regulation of Whaling (‘ICRW’); Whaling). The International Whaling Commission (‘IWC’) has been vested with the competence to amend the provisions of the so-called Schedule from time to time, which contains utilization and conservation standards. An amendment has to be adopted by a three-quarters majority vote (Art. III (2) ICRW), which is followed by a comprehensive opting out procedure. Such amendment becomes effective for all parties, unless any party files an objection within a 90-day period. In this case, the time limit for opting out is automatically prolonged for another 90-day period. During this additional time period any other party has the opportunity to opt out in reaction to the other party's objection. Thereafter, the amendment enters into force for all those parties that have not notified their objections within the 180-day period. In 1982, the IWC adopted a moratorium on commercial whaling which entered into force in 1986. Norway, the former Soviet Union, Japan, and Peru lodged an objection to the moratorium which the latter two countries later withdrew. Iceland left the IWC in protest in 1992, but rejoined in 2002 with a reservation to the moratorium which was not recognized as a valid objection by some other contracting parties. A proposal made by Japan in 2005 to reinstitute commercial whaling did not reach the required three-quarters majority vote in the IWC.
17 This model was followed, with variations, by various conventions establishing Regional Fisheries Management Organizations. Although the amendment procedures are slightly different from each other, they follow the same basic pattern: Fisheries Commissions (Fisheries, Commissions and Organizations) such as the one established by the Northwest Atlantic Fisheries Organization (‘NAFO’), the North-East Atlantic Fisheries Commission (‘NEAFC’), the International Commission for the Conservation of Atlantic Tuna (‘ICCAT’), the International Baltic Sea Fishery Commission (‘IBSFC’) and the Commission for the Conservation of Antarctic Marine Living Resources (‘CCAMLR’; Antarctica) adopt recommendations for conservation and management measures either by a majority vote or by consensus. An objection by a contracting party leads to an additional time period to give other parties the possibility to lodge an objection. Some of the conventions stipulate that if a certain number of parties have objected to a recommendation, it does not become binding on any party. In addition, under the NEAFC and NAFO conventions contracting parties may withdraw from a recommendation one year after it has entered into force. The 2001 Convention on the Conservation and Management of Fishery Resources in the South-East Atlantic Ocean contains an innovative provision with regard to opting out. A party which makes an objection is required to provide a written explanation of its reasons and, where appropriate, its proposals for alternative measures which it will implement (Art. 23 (1) (d)). This is an important step towards more transparency in the opting out procedure which could be a model for future environmental treaties.
4. International Criminal Law
18 The Review Conference for the Rome Statute of the International Criminal Court (ICC) in Kampala in 2010 adopted a resolution with amendments to the Rome Statute to introduce a definition and define the jurisdiction of the ICC for the crime of aggression (see Resolution RC/Res.6). This amendment is open for ratification, yet in accordance with Art. 15 bis (2) Rome Statute 30 ratifications are required prior to its entry into force. Within the new Art. 15 bis Rome Statute, para. 4 includes a provision stating that ‘[t]he Court may […] exercise jurisdiction over a crime of aggression, arising from an act committed by a State Party, unless that State has previously declared that it does not accept such jurisdiction by lodging a declaration with the Registrar’. Taken at face value, this clause incorporates an opting out procedure for the exercise of jurisdiction by the court in cases of State referral or propiomotu investigations. The actual relevance of this clause, however, remains opaque, because the final resolution from 2010 stated that the amendment was adopted in accordance with Art. 121 (5) Rome Statute. Thus, in accordance with the plain meaning of this procedure, any State would only be bound by the amendment in its entirety upon ratification, thereby rendering an additional opting out procedure potentially useless. The alternative would have been to conclude the amendment under Art. 121 (4) Rome Statute, which permits to adopt amendments through ratification by a majority of seven-eighths of the Member States.The legal effect of the opting out provision, as it has been adopted,is consequently open to be settled by State practice (for details see Heinsch 734 and van Schaack 528).
C. Treaty-Making or Law-Making Character?
19 The tacit consent/opting out procedure can either be classified as a modified treaty-making or as an international legislative procedure (International Legislation). Whereas international treaty-making is based on the principle of consent as an emanation of State sovereignty, international legislation is characterized by the adoption of binding rules by a (qualified) majority vote without requiring the subsequent ratification, acceptance, or approval by the States concerned. Consequently, States can be bound by the decision of an international organization or a treaty body without or even against their will. Under traditional international law, consent of a State to be bound by a treaty was the underlying principle which is codified in Art. 11 VCLT. Even if States are generally free to agree on any means of expressing their consent, the close connection between the classic methods mentioned in the first part of Art. 11 VCLT and the ‘other means’ referred to in its second part seem to suggest that all these means are supposed to have certain common features, namely that consent has to be expressed by some positive action, and that it can only be given to provisions that are already in existence and known to the State concerned. In the case of tacit consent/opting out procedures, this traditional mode of treaty-making has been modified. States Parties pre-agree to a special simplified procedure creating legally binding rules by majority vote, but leaving them the possibility of avoiding the legally binding effect by objecting. The consent to the treaty providing for a simplified amendment procedure could thus be construed as including the anticipatory consent to future amendments. This interpretation is, however, a pure legal fiction because the content of future amendments is not even foreseeable at the time the consent is expressed. Alternatively, consent could be construed as having been given by silence or by the omission to object (Acquiescence). From this perspective, the tacit consent/opting out procedure turns the classical affirmative acceptance procedure upside down. It makes use of a legal presumption agreed upon in the underlying treaty, namely that silence, ie the failure to object, shall be treated as if consent has been given. It can, therefore, be characterized as a modification/adaptation of treaty law to an urgent need for a more flexible and rapid amendment procedure.
20 An argument for the law-making character of the procedure is the adoption of amendments by majority vote without the need for ratification or individual acceptance. However, States cannot be bound against their will because of the opportunity to opt out. Such an option, which is frequently combined with a prohibitive quorum, is a safeguard for the principle of consent and protects State sovereignty. Therefore, the tacit consent/opting out procedure does not fall into the category of genuine international legislation either. It rather combines the objective of efficient and timely international standard-setting with the interest of States to retain their freedom to decide. To point out its intermediate status between treaty-making and law-making, it can be characterized as quasi-legislation or indirect law-making. As such it can be considered an innovation in international law-making which, however, stops short of international legislation, because States are reluctant to endow international bodies with legislative powers. This is not only due to governments’ preference to retain as much sovereign power as possible, but also to the democratic principle because national parliaments do not take part in this rule-making process (see also Democracy, Right to, International Protection).
21 Although the tacit consent/opting out procedure had at first been criticized as violating the cardinal legal principle of consent, it has stood the test of time and is frequently used in contemporary international law for a variety of subjects. As the above-mentioned examples have shown, this dynamic and flexible procedure is not only used to adapt technical and scientific standards but also, at least in some cases, to modify or expedite core treaty obligations. Such cases are closely related with environmental protection and the preservation of natural resources. These objectives are in the interest of all States, or to put it differently, in the community interest. This observation allows the conclusion that the tacit consent/opting out procedure is increasingly used as a law-making method to accommodate community interests within a reasonable time frame. In State practice, it has proved to be an effective method of international law-making, and States rarely avail themselves of the possibility to opt out. Nevertheless, it has to be acknowledged that certain subject-matters such as the protection of common goods and common values give rise to the need to promulgate legal norms that are binding on all States, without exception (Obligations erga omnes). In order to solve this problem, the international community will have to develop further legislative procedures which go beyond the tacit consent/opting out procedure.
- AD McNair The Law of Treaties (OUP London 1961).
- CH Alexandrowicz The Law-Making Functions of the Specialised Agencies of the United Nations (Angus & Robertson Sydney 1973).
- AO Adede ‘Amendment Procedures for Conventions with Technical Annexes: The IMCO Experience’ (1976–77) 17 VaJIntlL 201–15.
- BO Okere ‘The Technique of International Maritime Legislation’ (1981) 30 ICLQ 513–36.
- M Vierheilig Die rechtliche Einordnung der von der Weltgesundheitsorganisation beschlossenen regulations (v Decker Heidelberg 1984).
- P Rösgen Rechtsetzungsakte der Vereinten Nationen und ihrer Sonderorganisationen (Doctoral thesis Bonn University 1985).
- G Palmer ‘New Ways to Make International Environmental Law’ (1992) 86 AJIL 259–83.
- C Tomuschat ‘Obligations Arising for States without or against Their Will’ (1993) 241 RdC 195–374.
- B Simma ‘From Bilateralism to Community Interest in International Law’ (1994) 250 RdC 217–384.
- FL Kirgis Jr ‘Shipping’, in O Schachter and C Joyner (eds) United Nations Legal Order vol 2 (CUP Cambridge 1995) 715–51.
- FL Kirgis Jr ‘Specialized Law-Making Processes’, in O Schachter and C Joyner (eds) United Nations Legal Order vol 1 (CUP Cambridge 1995) 109–68.
- P Birnie ‘The Case of the Convention on Trade in Endangered Species’, in R Wolfrum (ed), Enforcing Environmental Standards: Economic Mechanisms as Viable Means? (Springer Berlin 1996) 233–64.
- J Sommer ‘Environmental Law-Making by International Organizations’ (1996) 56 ZaöRV 628–67.
- M Fitzmaurice ‘Expression of Consent to be Bound by a Treaty as Developed in Certain Environmental Treaties’, in J Klabbers and R Lefeber (eds), Essays on the Law of Treaties (Nijhoff The Hague 1998) 59–80.
- PH Sand Transnational Environmental Law (Kluwer Law International The Hague 1999).
- C Tietje ‘The Changing Legal Structure of International Treaties as an Aspect of an Emerging Global Governance Architecture’ (1999) 42 GYIL 26–55.
- R Churchill and G Ulfstein ‘Autonomous Institutional Arrangements in Multilateral Environmental Agreements: A Little-Noticed Phenomenon in International Law’ (2000) 94 AJIL 623–59.
- C Redgwell ‘Multilateral Environmental Treaty-Making’, in V Gowlland-Debbas (ed), Multilateral Treaty-Making (Nijhoff The Hague 2000) 89–107.
- JD Aston Sekundärgesetzgebung internationaler Organisationen zwischen mitgliedstaatlicher Souveränität und Gemeinschaftsdisziplin (Duncker & Humblot Berlin 2005).
- J Brunnée ‘Reweaving the Fabric of International Law? Patterns of Consent in Environmental Framework Agreements’, in R Wolfrum and V Röben (eds), Developments of International Law in Treaty-Making (Springer Berlin 2005) 101–26.
- M Fitzmaurice 'Consent to be Bound—Anything New under the Sun?' (2005) 74 NordicJIL 483–507.
- G Handl ‘International “Lawmaking” by Conferences of the Parties and Other Politically Mandated Bodies’, in R Wolfrum and V Röben (eds), Developments of International Law in Treaty-Making (Springer Berlin 2005) 127–43.
- R Heinsch 'The Crime of Aggression after Kampala: Success or Burden for the Future?' (2010) 2 Goettingen Journal of International Law 713–43.
- B van Schaack 'Negotiating at the Interface of Power and Law: The Crime of Aggression' (2010–2011) 49 ColumJTransnatlL 505–600.
- O Corten and P Klein (eds) The Vienna Convention on the Law of Treaties: A Commentary, vols 1–2 (OUP Oxford 2011).
- ML McConnell D Devlin and C Doumbia-Henry The Maritime Labour Convention, 2006 (Nijhoff Leiden 2011).
- O Dörr and K Schmalenbach (eds) Vienna Convention on the Law of Treaties: A Commentary (Springer Heidelberg 2012).
- DB Hollis (ed) The Oxford Guide to Treaties (OUP Oxford 2012).
- Kirsten Schmalenbach 'The Crime of Aggression before the International Criminal Court' in HP Hestermeyer and others (eds) Coexistence, Cooperation and Solidarity-Liber AmicorumRüdigerWolfrum vol 2 (Nijhoff Leiden 2012) 1259–1281.
- Constitution and Convention of the International Telecommunication Union (with Annexes and Optional Protocol) (concluded 22 December 1992, entered into force 1 July 1994) 1825 UNTS 143.
- Constitution of the World Health Organization (signed 22 July 1946, entered into force 7 April 1948) 14 UNTS 185.
- Convention on the Intergovernmental Maritime Consultative Organization (done 6 March 1948, entered into force 17 March 1958) 198 UNTS 3.
- Convention of the World Meteorological Organization (with Annexes and Protocol concerning Spain) (done 11 October 1947, entered into force 23 March 1950) 77 UNTS 143.
- Convention on International Civil Aviation (signed 7 December 1944, entered into force 4 April 1947) 15 UNTS 295.
- Convention on International Trade in Endangered Species of Wild Fauna and Flora (opened for signature 3 March 1973, entered into force 1 July 1975) 993 UNTS 243.
- Convention on the Conservation and Management of Fishery Resources in the South East Atlantic Ocean (done 20 April 2001, entered into force 13 April 2003) 2221 UNTS 189.
- Convention on the Conservation of Migratory Species of Wild Animals (concluded 23 June 1979, entered into force 1 November 1983) 1651 UNTS 333 (Bonn Convention).
- Convention on the Protection of the Marine Environment of the Baltic Sea, (with Annexes) (adopted 9 April 1992, entered into force 17 January 2000) 2099 UNTS 195.
- Convention on the Transboundary Effects of Industrial Accidents (done 17 March 1992, entered into force 19 April 2000) 2105 UNTS 457.
- Maritime Labour Convention (adopted23 February 2006, not yet entered into force) <http://www.ilo.org/> (27 January 2013).
- Review Conference to the Rome Statute of the International Criminal Court ‘Resolution RC/Res.6: The Crime of Aggression’ (11 June 2010) <http://www.icc-cpi.int/> (27 January 2013).
- Protocol to the 1979 Convention on Long-Range Transboundary Air-Pollution on Further Reduction of Sulphur Emissions (adopted 14 June 1994, entered into force 5 August 1998) 2030 UNTS 122.
- Vienna Convention on the Law of Treaties (with Annex) (concluded 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331.