Concept of State Succession

Meaning and Definition

State Succession in international law refers to the transfer of rights, obligations, and responsibilities from a predecessor State (the State that has undergone a change) to a successor State (the State that has replaced it) concerning a particular territory.

The concept becomes relevant whenever there is a change in sovereignty over a territory, regardless of how that change occurs. This can happen in various situations:

Uniting of States: Two or more States merge to form a new single State (e.g., unification of Germany).
Separation of Parts of a State: A part of a State separates to form a new State (e.g., South Sudan separating from Sudan).
Dissolution of a State: A State ceases to exist and is replaced by several new States (e.g., dissolution of Czechoslovakia, dissolution of the Soviet Union).
Succession in respect of part of territory (Cession/Transfer): A part of the territory of a State is transferred to another State (e.g., cession of territory by treaty).
Decolonization: A non-self-governing territory becomes an independent State (e.g., India's independence from Britain).

State succession is a complex area of international law, and there is no single universally accepted comprehensive set of rules governing all situations. However, principles have developed through State practice, judicial decisions, and codification efforts (like the Vienna Convention on Succession of States in respect of Treaties, 1978, and the Vienna Convention on Succession of States in respect of State Property, Archives and Debts, 1983 - though these Conventions are not widely ratified and their provisions reflect customary law to varying degrees).

Definition

The Vienna Convention on Succession of States in respect of Treaties, 1978 (Article 2(1)(b)) provides a definition:

"'succession of States' means the substitution of one State for another in the responsibility for the international relations of territory."

Explanation:

Substitution of States: One State replaces another as the sovereign authority over a territory.
Responsibility for International Relations: The successor State takes over the predecessor State's role in representing the territory in international affairs.
The definition focuses on the factual change in responsibility for international relations, not necessarily a judgment on the legality of the change.

Transfer of rights and obligations from one state to another

The central issue in state succession is determining which rights and obligations of the predecessor State continue to be binding or accrue to the successor State concerning the territory in question. This transfer is not automatic for all rights and obligations; specific rules and principles apply depending on the type of succession and the nature of the right or obligation.

Example: If State A's territory is annexed by State B, does State B automatically become bound by all treaties State A had signed concerning that territory? Does State B become liable for all debts State A had incurred?

The general principle is that State succession should ideally not unduly disrupt established international relations and the rights of individuals and other states, but balancing this with the sovereign rights of the successor State is complex.

Example 1. Two neighbouring States, State X and State Y, merge to form a new single State, State Z. State X had previously signed a treaty with State A concerning border trade. Does State Z automatically become a party to this treaty?

Answer:

This is a situation of state succession by uniting of states. According to the principle of "clean slate" which generally applies to newly independent states (decolonization), new states start fresh without being bound by predecessor treaties. However, in cases of uniting or absorption of states, the general approach is often continuity, especially for localized obligations. The Vienna Convention on Succession of States in respect of Treaties, 1978 (not universally ratified) suggests that when two states unite, any treaty in force at the date of succession in respect of either state continues in force in respect of the successor state (unless certain exceptions apply). State practice is mixed, but there is a tendency towards continuity for treaties affecting the territory. So, State Z would likely become bound by the treaty State X had with State A, particularly as it relates to border trade which affects the former territory of State X, unless State Z and State A agree otherwise, or the treaty's nature is incompatible with the union. The specific rules depend on the nature of the treaty and the agreement between the uniting states and third states.

Rights and Obligations Subject to Succession

The effects of State succession vary depending on the category of rights and obligations in question. Certain categories are generally considered to pass to the successor State, while others may or may not, or are subject to specific rules.

Treaties

The effect of state succession on treaties is complex and depends on the type of succession and the nature of the treaty. The Vienna Convention on Succession of States in respect of Treaties, 1978 provides rules, but State practice is not always consistent with the Convention, especially for types of succession other than decolonization.

"Clean Slate" Principle (for Newly Independent States/Decolonization): Generally, a newly independent State that emerges from colonial rule is not automatically bound by treaties entered into by the former colonial power concerning that territory. The new State starts with a "clean slate" and can decide which treaties it wishes to continue to be bound by, usually through notification of succession. This principle protects the self-determination of the new State.
Continuity Principle (for Uniting, Separation, Dissolution - with exceptions): In other types of succession (uniting of states, separation of parts of a state, dissolution), there is a greater tendency towards continuity of treaties, especially those that are 'localized' or 'territorial' (affecting the specific territory, e.g., boundary treaties, treaties concerning water navigation). However, even here, certain treaties may terminate, particularly if their object and purpose are incompatible with the new situation, or if the parties agree otherwise.
Localized Treaties: Treaties concerning a specific territory (e.g., rights of passage over a river, boundary treaties) are more likely to be considered binding on the successor State.
Political Treaties: Treaties of a highly political nature (e.g., treaties of alliance, membership in international organizations) generally do not pass to the successor State automatically.

The successor State often enters into agreements with other States or makes unilateral declarations indicating which treaties it considers itself bound by or intends to continue.

Property, rights and interests

Generally, State property located in the territory to which succession relates passes to the successor State. This includes movable and immovable property, and assets of the predecessor State used for governmental purposes in that territory.

State Property: Public buildings, land, movable assets (vehicles, equipment) belonging to the predecessor State and located in the territory pass to the successor State.
Rights and Interests: Rights of the predecessor State relating to the territory (e.g., rights under contracts concerning public works, concessions) generally pass to the successor State.
Private Property Rights: Succession of States does not generally affect private property rights of individuals or entities within the territory. These rights continue to be governed by the domestic law of the successor State.

The Vienna Convention on Succession of States in respect of State Property, Archives and Debts, 1983 (not widely ratified) provides detailed rules on the allocation of State property upon succession, which reflect some degree of customary law.

Public debts

Public debts of the predecessor State are another complex area. The general approach varies depending on the type of succession:

Newly Independent States (Decolonization): The "clean slate" principle often applies. Newly independent States are generally not automatically bound by the public debts of the former colonial power, unless the debt was specifically attached to the territory or was for the benefit of the territory and the new State agrees to assume it.
Uniting, Separation, Dissolution: In these cases, the public debts are usually allocated among the successor States in an equitable proportion, often determined by agreement between the successor States. Factors considered may include the assets transferred, the population, and the territory's contribution to the debt.

Agreements between the predecessor and successor States, or among the successor States themselves, play a significant role in determining the allocation of public debts.

Matters not affecting the regime of the treaties (This seems like a reference to certain categories of treaties or obligations, perhaps those of a universal nature or those specifically excluded from the clean slate principle).

Some treaties or obligations are considered to have a special character and may be binding on a successor State regardless of the general rules on treaty succession. These include:

Boundary Treaties (*Uti Possidetis* principle): Treaties establishing boundaries are generally considered binding on successor States. The principle of *uti possidetis* (as you possess) emphasizes the continuity of existing administrative boundaries as international frontiers upon independence, promoting stability.
Treaties creating Objective Regimes: Treaties establishing rights or obligations of a universal character, like those concerning international waterways or straits, or potentially certain disarmament treaties, might be seen as creating objective regimes binding on whoever controls the territory, although this is debated.
Human Rights Obligations: There is a growing view, though not without debate, that fundamental human rights obligations are so important that they may be considered as continuing to apply to a successor State in respect of the population in the territory, based on universal values and *jus cogens* norms.

Membership in International Organizations:

Membership in international organizations is generally not automatically transferred upon state succession. The successor State typically needs to apply for membership, subject to the rules and criteria of the organization.

State Responsibility:

Obligations arising from the predecessor State's wrongful acts generally do not pass to the successor State, especially if the wrongful act did not create a specific debt or obligation attached to the territory. However, issues can arise concerning responsibility for continuous wrongful acts.

Example 1. When India became independent in 1947, did it automatically become a party to all treaties that the British Empire had signed concerning the territory of India?

Answer:

No, when India became independent in 1947 (a case of decolonization), it was generally subject to the "clean slate" principle regarding treaty succession. India was not automatically bound by all treaties entered into by the British Empire concerning the territory of India. India had the option to decide which treaties it wished to continue to be a party to, usually by notifying its succession to those treaties. However, certain treaties of a localized or territorial nature (e.g., boundary agreements) were generally considered as continuing to apply based on principles like *uti possidetis* and the need for stability. For most other treaties, India had the choice to succeed.

Example 2. Country A dissolves into two new States, Country B and Country C. Country A had a significant public debt. How is this debt likely to be handled under international law?

Answer:

In a case of dissolution, the public debts of the predecessor State (Country A) are generally allocated among the successor States (Country B and Country C) in an equitable proportion. This allocation is usually determined by agreement between Country B and Country C. If they cannot agree, principles of international law (like those in the 1983 Vienna Convention) suggest considering factors such as the assets transferred to each successor State, their respective populations, and the extent to which the debt was used for the benefit of their territories. The successor States are expected to negotiate and come to an arrangement regarding the division of the debt. There is no automatic transfer of the entire debt to just one successor State unless agreed upon.

Types of State Succession

Succession in cases of Universal Succession

State succession events can be broadly categorized based on the extent of the change to the predecessor State. Universal Succession occurs when the predecessor State entirely ceases to exist and is completely absorbed or replaced by one or more successor States.

Characteristics of Universal Succession:

The international legal personality of the predecessor State is extinguished.
The entire territory of the predecessor State becomes the territory of the successor(s).

Merger (or Uniting of States)

Merger occurs when two or more existing States unite to form a new single State, and the predecessor States cease to exist. The new State becomes the successor State to the territories of the merged entities.

Example: The unification of West Germany and East Germany in 1990. West Germany effectively absorbed East Germany, and the unified Germany is the successor State. (Sometimes also viewed as absorption). Another example is the formation of Tanzania from the merger of Tanganyika and Zanzibar in 1964.

In cases of merger, there is a stronger tendency in State practice towards the continuity of treaties and obligations of the predecessor States, particularly for treaties affecting the territory, although the new unified State may negotiate with other states to clarify or modify treaty relationships.

Dissolution

Dissolution occurs when a State ceases to exist and breaks up into several new independent States. The predecessor State's international personality is terminated, and multiple successor States emerge on its former territory.

Example: The dissolution of Czechoslovakia into the Czech Republic and Slovakia in 1993. The dissolution of the Soviet Union into several independent states in 1991.

In cases of dissolution, the approach to treaty succession is more complex. While some continuity is seen for localized treaties, the emerging States are often treated more akin to newly independent states regarding their general treaty obligations, though with some recognition of shared heritage and potential for agreement on succession to certain treaties (often through 'notification of succession' or 'agreement' among successor states and with third states). Public debts are typically allocated among the successor States by agreement.

Example 1. The country of Yugoslavia dissolved into several independent states (e.g., Serbia, Croatia, Slovenia). What type of state succession is this, and does the former Yugoslavia continue to exist as a subject of international law?

Answer:

This is a case of Universal Succession by Dissolution. The predecessor State (Yugoslavia) ceased to exist and broke up into multiple new States. The former Yugoslavia does not continue to exist as a subject of international law; its international legal personality was extinguished upon dissolution. The new States that emerged are the successor States on the former territory of Yugoslavia.

Succession in cases of Partial Succession

Partial Succession occurs when a part of the territory of a State becomes the territory of another State, while the predecessor State continues to exist, albeit with a reduced territory. In these cases, the international legal personality of the predecessor State is not extinguished.

Characteristics of Partial Succession:

The international legal personality of the predecessor State continues.
Only a part of the predecessor State's territory is involved in the succession.

Cession of territory

As discussed under acquisition/loss of territory, cession is the transfer of sovereignty over a part of a State's territory to another State by agreement (usually treaty). The ceding State continues to exist, but loses sovereignty over the ceded part. The acquiring State (to whom the territory is ceded) acquires sovereignty over that part.

Example: Transfer of a border area between two countries as part of a boundary settlement. The ceding State loses that part, and the acquiring State gains it. The Cession of Pondicherry and other French territories to India in 1962 by treaty is an example where France (predecessor State) ceded territory to India (successor State), and both States continued to exist.

Regarding treaties, those that applied exclusively to the ceded territory might cease to apply to the ceding State and begin to apply to the acquiring State, depending on the nature of the treaty and agreement. Treaties of the ceding State continue to apply to its remaining territory, and treaties of the acquiring State extend to the newly acquired territory (principle of moving treaty-frontiers).

Secession

Secession occurs when a part of a State breaks away to form a new independent State, while the predecessor State continues to exist with the remaining territory. The new State is the successor State to the territory that seceded. The predecessor State retains its international legal personality.

Example: South Sudan's secession from Sudan in 2011. Sudan (predecessor State) continued to exist with its remaining territory, and South Sudan became a new successor State.

In cases of secession, the 'clean slate' principle tends to apply more strongly to the newly seceded State regarding general treaties, similar to decolonization. The predecessor State continues to be bound by its treaties in respect of its remaining territory. Debts and assets are often allocated between the predecessor and successor states by agreement.

Decolonization (Formation of Newly Independent States)

This occurs when a non-self-governing territory (a colony) becomes an independent State. The former colonial power loses sovereignty over the territory, but it continues to exist as a State. The newly independent territory becomes a new successor State.

Example: India's independence from the UK in 1947. India is a successor State; the UK continues to exist as a predecessor State (in relation to India). Pakistan's creation from parts of British India is a related complex case involving both decolonization and separation.

As discussed earlier, the 'clean slate' principle is most strongly associated with decolonization. The newly independent State typically starts free from the treaty obligations of the former colonial power, except for specific categories like boundary treaties.

Other cases of Partial Succession (less common or debated):

Lease of territory: Transfer of control over territory without transfer of sovereignty. Not true succession.
Grant of territory under Mandate or Trusteeship: Historically, these were arrangements where sovereignty was unclear, and the administering power did not acquire sovereignty.

The distinction between universal and partial succession, while useful for categorization, is not always clear-cut in practice (e.g., distinguishing dissolution from secession when a central authority collapses). The legal consequences of succession ultimately depend on the specific facts of each case, relevant international law principles (including treaties and custom), and agreements between the states involved.

Example 1. The government of Country A transfers control over a strategically important port and a small surrounding area within its territory to Country B for a period of 99 years, but explicitly retains sovereignty over the territory. Is this a case of state succession?

Answer:

No, this is generally not considered a case of state succession. State succession involves the substitution of one State for another in the *responsibility for the international relations of territory* (transfer of sovereignty). In this example, Country A explicitly retains sovereignty; it only transfers control or administration for a limited period. There is no transfer of ultimate sovereign authority. This arrangement is more akin to a long-term lease of territory or grant of administrative rights, rather than a transfer of sovereignty constituting state succession.