State succession refers to the legal consequences that arise when one State replaces another in the responsibility for the international relations of a territory. It is an important concept in Public International Law because the replacement of one State by another raises questions concerning treaties, State property, debts, nationality, membership in international organisations and other international rights and obligations.
- Meaning of State Succession
- Predecessor State
- Successor State
- State Succession vs Change of Government
- Types of State Succession
- Transfer of Territory
- Secession or Separation
- Dissolution
- Unification or Merger
- Decolonisation
- Succession to Treaties
- Territorial Treaties
- Boundary Treaties
- Political Treaties
- Succession to State Property
- Succession to State Debts
- Succession to Nationality
- Succession to International Organisations
- State Succession and International Personality
- Clean Slate Principle
- Continuity Principle
- Clean Slate vs Continuity
- State Succession and State Responsibility
- State Succession and International Claims
- State Succession and Archives
- State Succession and Boundaries
- Important Examples
- Important International Instruments
- State Succession and Recognition
- State Succession and Self-Determination
- State Succession and Treaties: Basic Approach
- Common Confusions
- Topic at a Glance
- Quick Revision
- Conclusion
State succession must be distinguished from a change of Government. A change of Government normally leaves the international identity of the State intact, whereas State succession involves a change in the State responsible for the international relations of a territory.
Meaning of State Succession
State succession occurs when one State, known as the successor State, replaces another State, known as the predecessor State, in responsibility for the international relations of a territory.
The basic structure is:
Predecessor State β Change affecting territory β Successor State
The legal consequences depend upon the type of succession and the particular subject involved.
Predecessor State
The predecessor State is the State that was previously responsible for the international relations of the territory.
For example, if State A transfers territory to State B:
State A = Predecessor State
State B = Successor State
Successor State
The successor State is the State that replaces the predecessor State in responsibility for the international relations of the territory.
A successor State may emerge through:
- transfer of territory;
- separation;
- dissolution;
- unification;
- decolonisation.
State Succession vs Change of Government
| State Succession | Change of Government |
|---|---|
| Concerns replacement of one State by another | Concerns change in government |
| International identity may change | State normally continues |
| May involve territorial change | Territory normally remains the same |
| Questions of succession arise | Existing international obligations generally continue |
| New State may become successor | New Government represents the same State |
This distinction is fundamental.
Types of State Succession
State succession may take different forms depending upon the circumstances.
The major forms include:
- Transfer of territory
- Secession or separation
- Dissolution of a State
- Unification or merger of States
- Decolonisation
Transfer of Territory
Transfer of territory occurs when part of the territory of one State becomes part of another State.
The predecessor State continues to exist, while sovereignty over the transferred territory changes.
For example:
State A β Territory transferred β State B
State A remains in existence, but the transferred territory becomes part of State B.
Secession or Separation
Secession occurs when part of the territory of an existing State separates and forms a new State.
The original State continues to exist, while the new State becomes the successor State in relation to the separated territory.
The legal consequences may concern:
- treaties;
- State property;
- debts;
- nationality;
- international organisations.
Dissolution
Dissolution occurs when an existing State ceases to exist and is replaced by two or more States.
Unlike secession, the predecessor State itself disappears.
For example:
State A β State A ceases to exist β States B + C + D
The resulting States become successor States.
Unification or Merger
Unification occurs when two or more States combine to form a single State.
The separate international identities of the predecessor States may be replaced by the international identity of the unified State.
The consequences concerning:
- treaties;
- property;
- debts;
- nationality;
- international membership;
depend upon the circumstances and applicable rules.
Decolonisation
Decolonisation involves the emergence of an independent State from a colonial territory.
The colonial power is replaced by the newly independent State in responsibility for the territoryβs international relations.
Decolonisation has played a major role in the development of modern rules concerning State succession.
Succession to Treaties
One of the most important questions in State succession is whether treaties of the predecessor State continue to apply to the successor State.
The answer may depend upon:
- the type of succession;
- the nature of the treaty;
- the territory concerned;
- the intention of the parties;
- applicable customary rules;
- specific treaty provisions.
Territorial Treaties
Treaties concerning territorial arrangements are generally treated differently from purely political treaties.
Certain territorial arrangements may continue despite a change in sovereignty because they are connected with the territory itself.
Examples may include arrangements concerning:
- boundaries;
- territorial status;
- rights over particular territories.
Boundary Treaties
Boundary treaties receive particular protection in State succession.
A change in sovereignty does not ordinarily invalidate an established international boundary merely because the State responsible for the territory has changed.
This reflects the importance of stability of international boundaries.
Political Treaties
Treaties that are closely connected with the political identity or policies of the predecessor State may not automatically continue in the same manner.
The treatment of such treaties depends upon the type of succession and applicable legal rules.
Succession to State Property
Another major issue concerns State property located in the territory affected by succession.
State property may include:
- government buildings;
- public land;
- archives;
- governmental equipment;
- financial assets.
The allocation of property depends upon the type of succession and the applicable rules.
Succession to State Debts
State succession may raise questions concerning the debts of the predecessor State.
Relevant considerations include:
- whether the debt is connected with the territory;
- the type of succession;
- agreements between the States;
- equitable allocation;
- applicable treaty or customary rules.
There is no single rule that applies identically to every form of succession.
Succession to Nationality
State succession may create important nationality questions.
People living in the affected territory may need to determine whether they become nationals of the successor State.
Issues may include:
- acquisition of nationality;
- loss of previous nationality;
- dual nationality;
- prevention of statelessness;
- right to choose nationality in certain circumstances.
Nationality questions are particularly significant in cases of dissolution, secession and decolonisation.
Succession to International Organisations
State succession may also affect membership in international organisations.
The result depends upon:
- the type of succession;
- the constitutional rules of the organisation;
- whether the successor is regarded as continuing the predecessor;
- the practice of the organisation.
A successor State does not automatically inherit every membership held by the predecessor State.
State Succession and International Personality
State succession can involve a change in international legal personality.
In cases of dissolution:
Predecessor State β Ceases to exist
and:
Successor States β Acquire separate international personalities
In cases of secession, however, the predecessor State may continue to exist while the new State acquires its own international personality.
Clean Slate Principle
The clean slate principle is particularly associated with newly independent States emerging from colonial rule.
Under this approach, the newly independent State is generally not automatically bound by all the treaties of the predecessor State merely because the territory was previously under colonial control.
The principle developed particularly in the context of decolonisation.
However, the application of the clean slate principle is not unlimited, particularly in relation to territorial and boundary arrangements.
Continuity Principle
The opposite approach emphasises continuity.
Under certain forms of succession, the successor State may continue obligations and rights previously associated with the predecessor State.
Continuity is particularly relevant where there is a close relationship between the predecessor and successor State or where the international community treats one State as continuing the legal personality of another.
Clean Slate vs Continuity
| Clean Slate | Continuity |
|---|---|
| New State begins with a relatively fresh treaty position | Existing legal relations continue |
| Particularly associated with decolonisation | More relevant in certain continuity situations |
| New State not automatically bound by all predecessor treaties | Successor may continue existing obligations |
| Territorial arrangements may receive separate treatment | Existing international relations may be preserved |
State Succession and State Responsibility
State succession also raises questions concerning responsibility for internationally wrongful acts committed before succession.
The consequences depend upon:
- the type of succession;
- the nature of the wrongful act;
- the relationship between predecessor and successor;
- applicable international rules.
State succession does not automatically transfer every responsibility of the predecessor State to the successor State.
State Succession and International Claims
International claims may also be affected by succession.
Questions may arise concerning:
- claims belonging to the predecessor State;
- claims relating to territory;
- diplomatic protection;
- State property;
- international responsibility.
The applicable rules depend upon the nature of the succession.
State Succession and Archives
State archives may include:
- governmental records;
- administrative documents;
- historical records;
- territorial records.
Their transfer may be important for the functioning of the successor State and for establishing historical and legal facts concerning the territory.
State Succession and Boundaries
One of the most important principles is the preservation of existing international boundaries.
A successor State generally does not acquire a right to disregard established boundaries merely because State succession has occurred.
This principle promotes:
- territorial stability;
- peaceful relations;
- certainty of borders;
- prevention of territorial disputes.

Important Examples
Dissolution of the Soviet Union
The dissolution of the Soviet Union illustrates questions concerning:
- succession;
- international organisations;
- treaties;
- State property;
- nationality.
Russia continued to occupy the Soviet Unionβs permanent seat on the UN Security Council, while other former Soviet republics emerged as independent States.
Dissolution of Yugoslavia
The dissolution of Yugoslavia produced extensive questions concerning:
- State succession;
- recognition;
- nationality;
- property;
- debts;
- treaty relations;
- international organisation membership.
The situation demonstrated the complexity of distinguishing between continuity and succession.
Czechoslovakia
The peaceful dissolution of Czechoslovakia into the Czech Republic and Slovakia provides an important example of dissolution.
The predecessor State ceased to exist and two successor States emerged.
Important International Instruments
The law of State succession has been addressed through international instruments, including:
- Vienna Convention on Succession of States in Respect of Treaties, 1978
- Vienna Convention on Succession of States in Respect of State Property, Archives and Debts, 1983
These instruments provide important frameworks for understanding succession, although their applicability and acceptance vary.
State Succession and Recognition
State succession should not be confused with recognition.
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.
Recognition may accompany State succession, but the two concepts are legally distinct.
State Succession and Self-Determination
Self-determination has played an important role in the emergence of new States, particularly in decolonisation.
Where a people exercises a recognised right to self-determination, the resulting creation of an independent State may produce questions of succession concerning:
- treaties;
- property;
- debts;
- nationality;
- international membership.
State Succession and Treaties: Basic Approach
A useful examination framework is:
Identify the type of succession
β
Identify the type of treaty
β
Determine whether territorial or personal obligations are involved
β
Apply the relevant rule of succession
This is preferable to assuming that all treaties automatically continue or automatically terminate.
Common Confusions
Is State succession the same as change of Government?
No. State succession concerns replacement of one State by another, while a change of Government normally leaves the State intact.
Does every territorial transfer create a new State?
No. A transfer of territory may occur while the predecessor State continues to exist.
Does secession destroy the original State?
Not necessarily. In secession, the original State generally continues while a new State emerges.
What happens in dissolution?
The predecessor State ceases to exist and successor States emerge.
Do successor States automatically inherit all treaties?
No. The answer depends upon the type of succession and the nature of the treaty.
Are boundary treaties automatically terminated?
No. Established boundaries are generally protected despite State succession.
Does a successor State automatically inherit all State debts?
No. Allocation depends upon the circumstances and applicable rules.
Does a successor State automatically acquire membership in every international organisation?
No. Membership depends upon the rules and practice of the relevant organisation.
Topic at a Glance
| Point | Position |
|---|---|
| Meaning | Replacement of one State by another in responsibility for a territory |
| Predecessor State | State previously responsible |
| Successor State | State replacing the predecessor |
| Main forms | Transfer, secession, dissolution, unification, decolonisation |
| Major issues | Treaties, property, debts, nationality, archives, organisations |
| Boundary treaties | Generally preserved |
| Clean slate | Particularly associated with newly independent States |
| State continuity | Relevant in certain forms of succession |
| Important instruments | Vienna Conventions of 1978 and 1983 |
| Key distinction | State succession β change of Government |
Quick Revision
- State succession occurs when one State replaces another in responsibility for the international relations of a territory.
- The previous State is the predecessor State.
- The replacing State is the successor State.
- Major forms include:
- transfer of territory;
- secession;
- dissolution;
- unification;
- decolonisation.
- State succession is different from a change of Government.
- Important consequences concern:
- treaties;
- State property;
- State debts;
- nationality;
- archives;
- international organisations;
- State responsibility.
- Boundary treaties generally continue despite succession.
- The clean slate principle is particularly associated with newly independent States.
- Continuity may apply in other forms of succession.
- A successor State does not automatically inherit every treaty, debt or international membership of the predecessor.
- The dissolution of the Soviet Union and Yugoslavia illustrates complex questions of State succession.
- The dissolution of Czechoslovakia provides an example of peaceful dissolution.
- The Vienna Convention on Succession of States in Respect of Treaties, 1978 deals with treaty succession.
- The Vienna Convention on Succession of States in Respect of State Property, Archives and Debts, 1983 deals with property, archives and debts.
- State succession may be connected with self-determination and decolonisation.
- The essential distinction is:
State succession concerns the replacement of one State by another in responsibility for a territory, whereas a change of Government normally leaves the international identity of the State unchanged.
Conclusion
State succession deals with the legal consequences arising when one State replaces another in responsibility for the international relations of a territory. It may occur through territorial transfer, secession, dissolution, unification or decolonisation. The principal legal questions concern the continuation or termination of treaties, allocation of State property and debts, nationality, archives, international organisation membership and responsibility for international obligations. The treatment of these matters depends heavily on the type of succession and the nature of the particular right or obligation involved. The clean slate principle has particular importance in the context of newly independent States, while continuity may be relevant in other situations. Above all, State succession must be distinguished from a mere change of Government, because succession may involve a change in the international legal identity responsible for a territory.