State succession refers to the replacement of one State by another in responsibility for the international relations of a territory. The types and modes of State succession explain the different circumstances in which such replacement may occur and determine the legal consequences for treaties, State property, debts, nationality and other international rights and obligations.
- Transfer of Territory
- Secession
- Dissolution
- Unification or Merger
- Decolonisation
- Incorporation
- Federation and State Succession
- Modes of State Succession
- Secession vs Dissolution
- Dissolution vs Unification
- Transfer of Territory vs Secession
- Decolonisation vs Secession
- State Succession and Boundaries
- State Succession and Treaties
- State Succession and State Property
- State Succession and State Debts
- State Succession and Nationality
- State Succession and International Organisations
- State Succession and Recognition
- State Succession and Statehood
- Important International Instruments
- Important Examples
- Common Confusions
- Topic at a Glance
- Quick Revision
- Conclusion
The principal modes are transfer of territory, secession, dissolution, unification or merger, and decolonisation.
Transfer of Territory
Transfer of territory occurs when a portion of the territory of one State is transferred to another State.
The predecessor State continues to exist, but it loses sovereignty over the transferred territory.
State A → Transfer of territory → State B
Here:
- State A remains in existence;
- State B acquires responsibility for the territory;
- succession is limited to the transferred territory;
- questions concerning treaties, property, nationality and administration may arise.
Example
The transfer of Alaska from Russia to the United States in 1867 is a historical example of territorial transfer.
Secession
Secession occurs when a part of the territory of an existing State separates and establishes itself as a new State.
The important feature is that the predecessor State continues to exist.
State A → Part separates → State B
The resulting situation therefore contains:
- the continuing predecessor State;
- the newly created successor State.
Legal Consequences
Secession may raise questions concerning:
- treaties;
- State property;
- State debts;
- nationality;
- international organisation membership;
- boundaries;
- archives.
Example
The emergence of Bangladesh from Pakistan in 1971 is commonly discussed in the context of separation and State succession.
Dissolution
Dissolution occurs when an existing State ceases to exist and is replaced by two or more States.
Unlike secession, there is no continuing predecessor State.
State A → State A disappears → States B + C + D
The successor States collectively replace the predecessor State.
Main Features
- predecessor State ceases to exist;
- two or more successor States emerge;
- each successor acquires its own international legal personality;
- questions of division of property, debts, archives and treaty relations arise.
Examples
The dissolution of Yugoslavia and Czechoslovakia are important examples.
Unification or Merger
Unification occurs when two or more States combine to form a single State.
State A + State B → State C
The separate international identities of the predecessor States may be replaced by the international personality of the unified State.
Main Features
- two or more States combine;
- a single State emerges;
- governmental and international institutions may be reorganised;
- questions concerning treaties, property, debts and nationality may arise.
Example
The unification of Germany in 1990 provides an important example of territorial and constitutional unification, although its precise legal character differs from a simple merger of two entirely separate States.
Decolonisation
Decolonisation involves the emergence of an independent State from a colonial territory.
The colonial power ceases to exercise sovereignty over the territory, and an independent State emerges.
Colonial State → Independence → New State
Decolonisation is particularly important in the development of modern rules concerning State succession.
Main Features
- colonial rule ends;
- the territory becomes independent;
- a new international legal personality emerges;
- questions arise concerning treaties, property, debts and nationality;
- the principle of self-determination is closely connected with the process.
Incorporation
Incorporation occurs when one State becomes incorporated into another State, with the latter continuing as the international legal person.
The incorporated State may cease to exist separately.
State A + State B → State A continues; State B absorbed
This differs from a merger where the legal identity of the resulting State may be newly constituted.
The exact legal character of incorporation depends upon the circumstances.
Federation and State Succession
The formation of a federation does not necessarily constitute State succession.
Where previously independent States establish a federal State, questions may arise concerning whether:
- the constituent States retain international personality;
- the federation becomes the sole international person;
- existing treaties continue;
- international responsibility is transferred.
The legal consequences depend upon the constitutional and international arrangements involved.
Modes of State Succession
The modes of succession can therefore be summarised as follows:
| Mode | What happens? | Predecessor State |
|---|---|---|
| Transfer of territory | Part of territory moves to another State | Continues |
| Secession | Part separates and becomes a new State | Continues |
| Dissolution | State breaks into two or more States | Ceases |
| Unification/Merger | Two or more States combine | Usually replaced by unified State |
| Decolonisation | Colony becomes independent | Colonial relationship ends |
| Incorporation | One State becomes incorporated into another | Incorporating State continues |
Secession vs Dissolution
This is one of the most important distinctions.
| Secession | Dissolution |
|---|---|
| Part of a State separates | Entire State breaks apart |
| Original State continues | Original State ceases to exist |
| New State emerges | Two or more successor States emerge |
| Continuing State remains | No continuing predecessor State |
| Example: Bangladesh, 1971 | Example: Czechoslovakia |
Dissolution vs Unification
| Dissolution | Unification |
|---|---|
| One State becomes several States | Several States become one |
| Predecessor disappears | Unified State emerges |
| Multiple successor States | One resulting State |
| Example: Czechoslovakia | Example: German unification |
Transfer of Territory vs Secession
| Transfer of Territory | Secession |
|---|---|
| Territory is transferred to an existing State | Territory separates to form a new State |
| Receiving State already exists | New State emerges |
| Predecessor continues | Predecessor generally continues |
| Sovereignty changes through transfer | New international personality emerges |
Decolonisation vs Secession
Decolonisation and secession may appear similar because a new State emerges from an existing territorial structure, but they have different historical and legal contexts.
Decolonisation
The territory exercises the right of self-determination against colonial rule.
Secession
A part of an existing State separates from that State.
The distinction is particularly important because the international legal framework concerning self-determination and colonial territories developed differently from the general rules concerning secession.
State Succession and Boundaries
Whatever the mode of succession, existing international boundaries receive particular importance.
State succession does not automatically give successor States a right to redraw established international boundaries.
The stability of boundaries helps prevent succession from becoming a source of territorial conflict.
State Succession and Treaties
Different modes of succession can produce different consequences for treaties.
A basic approach is:
Identify the mode of succession → Identify the treaty → Determine the applicable succession rule
Territorial and boundary treaties are generally treated differently from political or personal treaties.
State Succession and State Property
The distribution of State property depends upon the type of succession.
In dissolution, for example, property may have to be divided among several successor States.
In territorial transfer, property connected with the transferred territory may pass to the successor State according to the applicable rules.
State Succession and State Debts
State debts may also be affected differently depending upon the mode of succession.
In dissolution, debts may need to be allocated among successor States.
In territorial transfer, questions may arise concerning debts connected with the territory.
There is no single rule automatically applicable to every situation.
State Succession and Nationality
Nationality is particularly important where populations suddenly become subject to a new sovereign.
Questions may include:
- whether nationality changes automatically;
- whether individuals retain their previous nationality;
- whether dual nationality arises;
- whether individuals have a right to choose nationality;
- how statelessness can be avoided.
State Succession and International Organisations
The international status of successor States in international organisations depends upon the particular organisation and the circumstances of succession.
A successor State does not automatically inherit every membership of its predecessor.
The dissolution of the Soviet Union illustrates the importance of distinguishing continuity from succession in relation to international organisations.
State Succession and Recognition
Recognition often accompanies State succession but is conceptually different.
State Succession
Concerns the replacement of one State by another in responsibility for a territory.
Recognition
Concerns acceptance of the legal status of a State or Government.
Thus:
Succession ≠ Recognition
State Succession and Statehood
The emergence of a successor State normally involves questions of Statehood.
A newly emerging entity must possess the relevant characteristics required for Statehood.
Recognition by other States may have significant practical consequences, but recognition itself should not automatically be treated as the sole source of Statehood.
Important International Instruments
The principal international instruments dealing with State succession include:
Vienna Convention on Succession of States in Respect of Treaties, 1978
It addresses the consequences of State succession in relation to treaties.
Vienna Convention on Succession of States in Respect of State Property, Archives and Debts, 1983
It addresses succession concerning:
- State property;
- State archives;
- State debts.
These instruments provide important frameworks for analysing State succession.
Important Examples
Bangladesh, 1971
The emergence of Bangladesh from Pakistan provides an important example for discussions concerning separation, recognition and State succession.
Soviet Union, 1991
The dissolution of the Soviet Union demonstrates the complexity of succession and continuity, particularly concerning international organisation membership, treaties and State property.
Yugoslavia
The dissolution of Yugoslavia generated extensive questions concerning:
- recognition;
- State succession;
- nationality;
- property;
- debts;
- treaties;
- international organisations.
Czechoslovakia
The peaceful dissolution of Czechoslovakia into the Czech Republic and Slovakia provides a clear example of dissolution.
German Unification, 1990
German unification illustrates the legal complexity of combining territories and governmental structures and demonstrates why the precise circumstances of each succession must be examined.
Common Confusions
Does secession mean that the original State disappears?
No. In the typical case of secession, the original State continues to exist.
Does dissolution mean the original State continues?
No. In dissolution, the predecessor State ceases to exist.
Is transfer of territory the same as secession?
No. In territorial transfer, an existing State receives the territory; in secession, a new State emerges.
Is decolonisation simply secession?
No. Decolonisation has a distinct legal and historical basis connected with self-determination and the ending of colonial rule.
Does every merger create a completely new State?
Not necessarily. The precise legal character depends upon the arrangements and continuity of the States involved.
Does every change in territory constitute State succession?
No. The legal consequences depend upon whether responsibility for the international relations of the territory has actually changed.
Does State succession automatically transfer all treaties?
No. Treaty succession depends upon the mode of succession and the nature of the treaty.
Topic at a Glance
| Mode | Result | Predecessor |
|---|---|---|
| Transfer of territory | Territory passes to another State | Continues |
| Secession | Part becomes a new State | Continues |
| Dissolution | State breaks into several States | Ceases |
| Unification | Several States combine | Usually replaced by unified State |
| Decolonisation | Colony becomes independent | Colonial sovereignty ends |
| Incorporation | One State absorbed into another | Incorporating State continues |
Quick Revision
- State succession means replacement of one State by another in responsibility for a territory.
- The major modes are:
- transfer of territory;
- secession;
- dissolution;
- unification or merger;
- decolonisation;
- incorporation.
- In transfer of territory, the predecessor State continues.
- In secession, the original State continues while a new State emerges.
- In dissolution, the predecessor State ceases to exist.
- In unification, two or more States combine into one State.
- Decolonisation involves independence from colonial rule and is closely connected with self-determination.
- Incorporation involves one State becoming absorbed into another while the incorporating State continues.
- The consequences of succession may concern:
- treaties;
- State property;
- State debts;
- nationality;
- archives;
- boundaries;
- international organisation membership.
- Boundary arrangements generally receive particular protection.
- The Vienna Convention, 1978 deals with succession concerning treaties.
- The Vienna Convention, 1983 deals with State property, archives and debts.
- State succession is different from recognition.
- State succession is also different from a change of Government.
- The essential distinction is:
Secession preserves the identity of the original State, whereas dissolution brings the predecessor State to an end.
Conclusion
State succession can occur through several different modes, each producing different legal consequences. Transfer of territory involves the movement of territory from one existing State to another, while secession involves the emergence of a new State from part of an existing State without necessarily extinguishing the original State. Dissolution occurs when the predecessor State ceases to exist and several successor States emerge. Unification or merger brings previously separate States together, while decolonisation involves the emergence of an independent State from colonial rule. Incorporation represents another form in which one State becomes absorbed into another. The classification of the particular mode is essential because it determines the approach to treaties, property, debts, nationality, boundaries and international organisation membership. There is therefore no single rule applicable to every case of State succession; the legal consequences must be determined according to the specific mode and circumstances of succession.
