Typologies and the ‘Essential Juridical Character’ of Treaties

Legal scholarship, doctrine and practice differentiate between treaties. References to ‘peace treaties’, ‘environmental treaties’, ‘fundamental treaties’, ‘contract treaties’, ‘constitutional treaties’ and ‘self-executing treaties’ are a received part of public international law discourse. In his dissenting opinion in the South West Africa Cases of July 1966, Judge Tanaka spoke of the League Mandates’ ‘characteristics similar to law-making treaties’.1 In its judgment in the Loizidou Case, the European Court of Human Rights labelled the European Convention on Human Rights (ECHR)2 as a ‘law-making treaty’, with matching competences for the ‘Convention institutions’.3

Classifications of treaties are also not new. In his 1930 article for the British Yearbook of International Law, Lord Arnold McNair distinguished between the ‘widely differing functions and legal character of the instruments which it is customary to comprise under the term “treaty”’.4 Heinrich Triepel had earlier proposed a distinction between a Vertrag on the one hand and a Vereinbarung as a communal expression of identical wills on the other.5 More recently, Joseph Weiler has pointed to ‘differentiating factors of treaties’, with accordingly differing hermeneutics.6

This chapter aims to trace the classifications of treaties prevalent in international affairs and to examine their significance within the framework of the law of treaties and of international law in general. The findings make no claim to exhaustiveness, but they do further our understanding of the variety of treaty typologies in use and their legal meaning, with concomitant implications for the politics of treaty making and application. A first aim is to explore – in line with the original project of which this chapter is a part – which typologies of treaties are reflected in the 1969 Vienna Convention on the Law of Treaties (VCLT).7 As it turns out, the 1969 Vienna Convention, as is the case with the 1986 Vienna Convention on the Law of Treaties between States and International Organizations or between International Organizations,8 differentiates between treaties only sparingly. This is somewhat different when we look at international law (doctrine) at large, or at broader discourses, such as those concerning justice and effectiveness.

The following sections consider the use of ‘typology’ (rather than ‘taxonomy’) as a tool – with form, normative effect and content as the main distinctive elements (Section 2). The chapter then addresses some typologies based on form (Section 3); on normative effect – with special attention for the ‘law-making treaty’9 as this typification has a prominent place in public international law discourse (Section 4) – and on content (Section 5).