Skip to main content


3.1 International Conventions expressly recognised

Classification of agreements

Listed first in Article 38 are 'international conventions, whether general or particular, establishing rules expressly recognised by the contesting states'. (UN 1945) Some regard treaties as the most important source of international environmental law precisely because it expressly states the consent of the contracting parties to the treaty. A treaty is defined by the 1969 Vienna Convention on the Law of Treaties as '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' (UN 1969 p. 3). A fundamental point of this definition is that a treaty is a written agreement between states. Whether a non-state organisation can be a party to a treaty has been a contentious question. In 1986, the UN General Assembly convened a conference in Vienna with the purpose of drafting the Vienna Convention on the Law of Treaties between States and International Organisations or between International Organisations. However, this Convention is not yet in force.

There are different types of treaties such as bilateral treaties between two states or those that are multilateral between multiple states. A bilateral treaty is an agreement between two states establishing mutual rights and obligations between them. Unless explicitly intended by the two parties, bilateral treaties confer no rights or obligations on another state. A multilateral treaty is an agreement between three or more states. Treaties are also known by multiple alternative names including conventions, agreements, pacts and covenants. Whatever its name, a treaty is a contractual form of agreement between its parties who are bound according to the terms of their agreement. This poses the question, how can a treaty be a source of law beyond the obligations the treaty represents. The answer is that some treaties have a general legal standing and effect as opposed to more specific contractual agreements such as between two or a small number of states. The former are viewed as law-making treaties.

Law-making treaties are international instruments that represent new general rules of law amongst a large number of states. Examples of law-making treaties in international environmental law are:

Procedures governing international agreements

Bilateral treaties concerning an issue of mutual interest to the states involved signify bilateral negotiations between them. Such treaties are termed 'contract' treaties. Multilateral agreements on the other hand may involve multiple entities and considerations in their negotiations. This may lead to agreements which are law making. A multilateral treaty is typically initiated by a major concern prompting a study by an international institution such as the World Health Organization, the UN International Law Commission or the General Assembly itself. An outcome may be preliminary negotiations leading to an international conference with the aim of drafting a convention. Delegates at the conference must be authorised by their respective countries to act as their representatives. A delegate unauthorised to act on behalf of his or her state participates in the negotiations without legal effect (Article 8, Vienna Convention on the Law of Treaties).

Once draft language in the convention is agreed it is opened for signature. Participating states that then sign the treaty signify their agreement in principle to the document. Alternatively, a state not participating in the signing of the document may later formally accede to it. This has the effect of also binding that state in principle to the agreement. Signatures are usually subject to ratification for the treaty actually to come into force. Ratification is accomplished by the relevant organs of states consenting to be bound by the treaty. The treaty itself then comes into force when its specified minimum number of ratifications are formally exchanged or deposited. It should be noted that states have the option of ratifying a treaty with reservations. A state may opt to tend a reservation when it declines to accept a specific obligation or condition in the treaty. The effect of a reservation is that the state accepts the obligations of the treaty excluding that part of it specified in the reservation.

Once a treaty is in force, it is presumed, in accord with the Vienna Convention, that it binds the parties in good faith (UN 1969). The basic principle of law is pacta sunt servanda, 'agreements which are neither contrary to law, nor fraudulently entered into, should be adhered to in every manner'. This principle applies to the interpretation of the terms of the treaty in its practice. Article 31 of the Vienna Convention sets out general rules of interpretation. However, specifying rules for the interpretation of treaties is viewed as warranting caution.

Adherence to a treaty may become a question under two particular circumstances. A treaty may be terminated or otherwise affected when a state is succeeded wholly or in part by another or a new state. This has been a critical question for some African states after they gained their independence for example. Armed conflict may also terminate or suspend a treaty while hostilities continue. Article 60 of the Vienna Convention also provides for the situation arising when a party to the treaty is in material breach of its terms. Such a breach may be seen as grounds for termination of the treaty by other states. Similarly, a fundamental change from the original circumstances of the treaty may be invoked as grounds for its termination.

A more likely circumstance is a dispute between the parties to the treaty. For such contingencies, many treaties provide for settling disputes by conciliation through commissions. Mediation is another option. More formal legal options are arbitration and adjudication. Arbitration provides for the parties to determine the arbitration procedures including the appointment of arbitrators. Settlements achieved by arbitration are binding. The use of the International Court of Justice for adjudication may be less favoured in practice because it does not allow the discretion to states provided in the other methods of resolving disputes. The ICJ only has jurisdiction over cases brought to it by states. Cases are most frequently brought by the parties under compromis. The ICJ has some advantages over other methods of resolving disputes. It is a permanent body. Its procedures and accumulated jurisprudence also afford familiarity.