The length of this chapter demonstrates that this is an important topic, though it is often neglected. As also an international lawyer of some repute, La Fontaine is quite right: consideration of the duration and termination of a new treaty should not be left until the end of negotiations. Not only may the necessary provisions raise difficult technical questions, but they can also raise sensitive policy issues which should be discussed earlier rather than later in the negotiations. But, first, a note on terminology:

Part V of the Convention, Articles 42–5 and 54–64, set out the various circumstances in which a treaty can be denounced, terminated or its operation suspended, other than on grounds of invalidity (for which see the next, much shorter, chapter). Unless the treaty otherwise provides, a party claiming that it is not bound by the treaty has the onus of establishing this.