The 1978 Vienna Convention on the Succession of States in Respect of Treaties (`the 1978 Vienna Convention`) defines succession as `the replacement of a State by another person responsible for the international relations of the territory` (Article 2(1)(b)). The phenomenon is widespread: decolonization, unification and separation are the possible occurrences of state succession. Decolonization is the attainment of independence by a non-metropolitan territory. The unification of states is the merger of two or more states into a new entity. Predecessor States generally disappear; Otherwise, one of them continues to exist and the case is called absorption. Separation is the creation of the successor state(s), while the predecessor state persists. Dismemberment is comparable to separation, but all states disappear and two or more states are created. This taxonomy of state succession forms the traditional analytical grid used to represent and study state succession. The importance of categories of State succession cannot be overemphasized: these categories are the current starting point for the codification of State succession. Thus, the taxonomy of state succession represents both an important context in the study of state succession and an imaginative analytical framework. One way to deal with state succession is to start with abstract and general questions and then move on to concrete and specific issues.

We will try to present the succession of the State according to this scheme. State succession poses many problems, the first of which is the disappearance or emergence of a state, also known as state identity/continuity (see State Identity and Continuity). The legal succession of treaties is the best-known area of State succession, and the Vienna Convention on the Succession of States as far as treaties are concerned addresses this subject. The diversity of treaties includes a variety of treatments in the case of State succession; For example, humanitarian treaties and arms control treaties raise different types of issues. Succession of State responsibility is intended to make the successor State responsible for the injustice of its predecessor. The 1983 Vienna Convention on State Succession deals with three issues – debts, State property and archives – and expressly reserves the right to apply international debt conventions. The distribution and transfer of state assets is also tricky. States must agree on the assets of the succession and on the general principles of transition and distribution. Finally, individuals appear in the context of State succession by nationality and private rights and concessions. The concern of international law regarding nationality stems mainly from the desire to avoid cases of statelessness. The acquired rights of individuals or companies are threatened in the event of State succession.

This theory was advanced by Jellinek in 1900 and is another version of the theory of universal continuity. According to Jellinek, the successor State undertakes to respect the rules of international law and fulfils the obligations towards other States created under them. Although this theory assumes that the fulfilment of the obligation under international law is only a « moral duty » of the successor State, it also gives other States the right to insist that the successor State fulfil the existing obligation. If the successor State refuses recognition, the other States may even refuse recognition or make recognition conditional on acceptance of their obligation. 1.08 I have decided to consider the question of the succession of treaties and treaties, as these are the two main means by which States may decide to give their consent to international arbitration. It should be recalled that international arbitration is based on the principle of consent. A court`s jurisdiction over a dispute is based on the consent to arbitration given by both the claimant (almost always an investor) and the respondent (almost always the host State). The consent of the host Member State can be obtained in three different ways. First, consent can be found in a direct agreement between the investor and the host State (a so-called « state treaty »).

Second, consent may be contained in a provision of the national law of the host Member State.20 While in the former the host State consents to arbitration with a particular investor, in the latter case consent is given in a broad sense to any foreign investor (nationality) admitted to the country. Third, the consent of a host State to arbitration is contained in a provision contained in a contract concluded by that State and in the « country of origin » of the investor. Investment promotion and protection contracts generally contain a dispute settlement clause under which each State accepts in advance arbitration for claims filed by a national of the other Contracting State that meet certain requirements of the Treaty. This is the oldest theory of succession defended by Grotius, who uses the Roman analogy of succession to the death of a natural person.