State Succession under International Law


State succession under international Law is indeed a perplexing topic to discuss. After world war 2, state succession has become an extremely essential subject. As more than 100 new state came into existence due to decolonisation. Despite of failure to codify state succession law, there seems to be an emerging consensus in the recent practice among the learned scholars suggesting the state should try to manage legal relationship at all level.

As the Act is not codified, this topic is not governed by any specific method or rule and because of this complexity arises a lot. This topic takes into consideration various issues with respect to rights, duties, nationalities of the people and also issues related to properties, treaties, relation with international organisations and debts of the new successor state.

Historical background

Before 20th Century the political situation of the world was completely different. So as the method of government differed too along with rules and regulations. Those were the era of kings and kingdoms and annexation of the state was very common. There was no rules or treaties as to how the relation between the state will be governed. One king would dominate another’s kingdom out of power, thus resulting in the formation of new state continuously. This situation resulted in the creation of various problems like frequently changing rules and regulations, nationality, political and economic agendas and so on.

 Now, as we live in an organised society an organised rule is necessary to regulate the political and legal situation between the states.

Role of UN in regulating the state succession Act

UN being an intergovernmental organisation looks after the peace and security between the states. The international Law commission (ILC) being the head of the sate succession matters yet, failed to codified laws as how to  govern state succession issues, the UN has established certain guidelines to be followed when the new state comes into existence. These guidelines are basically to maintain peace and harmony and to deal with the situation arising out of new state formation, like internal problems of rights and duties and external issues related to membership of international organisation, debts and credits etc.

State succession under International Law

State succession can be defined as “The replacement of one state by another in the responsibility for the international relation of territory” Article 2(1)(b) of the Vienna convention act, 1978 . In another word when the state loose whole or part of its territory which results in the formation of one or more new states, and the relation of the  new emerged state  with the international state .

The parent state is called the predecessor state the new state formed out of it is called successor state.

Types of state succession

Partial: When one or more state is formed, from the predecessor state along with the predecessor state still in existence, is known as partial succession.

Example: a. separation of India from British

a. separation of  Pakistan from India

b. separation of Bangladesh from Pakistan

Universal: When the predecessor state is completely dissolve and vanished and one or several successor state forms out of it, is known as universal succession.

Example: a. Dissolution of Czechoslovakia

b. Division of USSR.

Theory of State Succession

Universal succession/ Popular continuity theory:  Both this theory are identical to one another. This is the oldest form of succession theory given by Grotius, Fiore and Fradie. According to this theory, the right and duties of the predecessor state transfer automatically to the succession state without any obstruction and alteration. Both these theories were largely criticised by other scholar due to its Roman law analogy and unclear explanation of state succession.

Organic Substitution theory:  Scholers like Von gierke and Max Huber supported this theory. According to the theory the new state that comes into existence continues with the old rule and regulations without any alteration. But, this theory too have been criticise because of invalid practical application.

Self- Abnegation theory: This theory was advocated by Jellinek in 1900. It is known as another version of universal continuity theory.According to this theory the successor state morally agrees to follow the rules of the international law and follow the obligation towards other state.

Negative Theory: This theory was established in the mid- 19th century. According to the theory the successor state is absolutely free from the right and obligation of the predecessor state. The Successor state can form their own rules and regulations, political, economic and social laws and also can create their own international relations.

Communist theory: According to this theory, the successor state is bound by certain rules and regulations, internal treaties debts and duties with the predecessor state. This theory is completely contradictory to the negative theory. When the successor state come into existence, they are bind by certain political and economic agendas. For instance, the issues related to paying of debts, agreements of war and peace, treaties etc.

Matters of state succession

  1. Treaties
  2. Membership of International Organisation
  3. Debts and loans
  4. Private and Public property
  5. Other rights and Duties

Treaties: The Vienna convention of state succession in respect of Treaties, 1978; was passed to deal with the laws related to treaties between the  states. While discussing matter relating to treaties, whether the newly formed state shall be bind with all the treaties which the predecessor state has signed. well, answering to this question a codified customary principal have evolved which says that the treaties related to the boundary is binding to the succeeding state and cannot be altered. Secondly, while discussing treaties related to Human rights the general discussion is that the successor state is not bound to follow, the successor state should have the right to decide if they want to continue with the treaty or not. Similarly, other treaties with respect to international states and organisation are not binding and the successor state can go for a fresh new treaty.  

Membership of International Organisation

Being as a member of international organisation has its own significance, own political visibility and diplomatic benefits. While dealing with the questions if the newly formed state is entitled to be the member of the International Organisation, it is said that the successor state have to fresh apply for the membership. A good example of India and Pakistan, when Pakistan separated from India the UN said that they have to again apply for the membership. Another example, when USSR got divided and various state came into existence along with Russia, complication raised as to whom the membership of UN security council  should be given, finally the issue was resolved through “Almaty declaration” and Russia was given the membership 

Debts and Loans:

Issues related to debts and loans also arises as who will repay it. The  best way to resolve this issue is by making agreement of bilateral nature between the predecessor state and the successor state as to how the loan will be paid back to the donor agencies or any other entities. But the rules related for the same is not codified and hence complexity arises.

Public and private Property: Public properties which includes movable and immovable properties  like houses, lands, railways, buses, planes, golds, embassies, Infrastructure etc., comes into question as what to do with those property. If the successor state are enjoying the property they should have the binding obligation to repay it. Well, in such case the new state is bound  to repay to the parent state.

While dealing with the personal property, the successor state have to make a rule and regulation as to how the properties should be distributed among the citizens.

Other rights and Duties: Other rights and duties like nationality of the citizen, obligations towards new authority and the state are taken into consideration. According to the guidelines laid by UN the newly formed state have the right to choose their nationality, but he reality speaks something else.


The topic seems to be extremely perplexing to understand, as the area is quite lengthy. Perhaps, due to its complexity and subject matter UN believe it’s difficult to codify the law. Theoretically and practically of the topic is yet to develop more, lot more development, flexibility and simplicity is required in this subject matter to deal with the law of state succession,  and the same is increasing with the time.

About Author: Dafadar Abul Bashar, Rizvi Law college, Bandra (Mumbai).

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