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This article is written by Arya Mittal from Hidayatullah National Law University. The article analyses the jurisprudence of the International Court of Justice in resolving boundary disputes between states.


Certain states are considered powerful while some are considered weak. This power to certain states might arise for different reasons such as their strength to conquer territories that belong to no one or other states. The territory has always been a cause of concern for certain countries due to its power, availability of resources, security reasons, etc. The International Court of Justice (ICJ) is the supreme authority to solve disputes between states as states are the subjects of international law. Sometimes, it even becomes complex and tough for the ICJ to rule on such cases owing to different factors, one such factor being the existence and validity of boundary agreements. In light of this, it is interesting to examine the jurisprudence of ICJ in solving boundary-related disputes and the same has been discussed in the subsequent sections.

Territorial sovereignty

The states are the main subjects of international law and each has its sovereignty. Its external sovereignty means that it is independent and is not subjected to control by other nations. One of the most common ways of exercising this external sovereignty is through the territory. Countries have their boundaries and within these boundaries, they exercise their sovereignty.

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Different jurists have defined the term differently. Brierly considers territorial sovereignty as the existence of rights of a state over a particular territory rather than the independence of a state. Judge Huber stated, “sovereignty, in relation to a portion of the surface of the globe, is the legal condition necessary for the inclusion of such a portion in the territory of any particular state”. The title specifies the territorial sovereignty of a state. As per Malcolm Shaw, it relates to both the factual and legal conditions under which territory is deemed to belong to one particular authority or another. To simplify, it means the existence of some facts which create a legal right over territory to a particular authority.

Title over any territory can be obtained through different modes such as international treaties and agreements, gaining sovereignty over terra nullius (territory over which there is no sovereign), arbitration, etc.

Boundary disputes

In simple terms, boundary disputes refer to disputes between two or more independent states over the division of land or sea. In most cases, such states enter into treaties to demarcate the area (as evident in the cases discussed hereafter). However, due to the faulty interpretation of the treaty, it might happen that one of the parties later contravened the treaty, which gives rise to a boundary dispute. Yet another reason could be the political interests of the states or undiscovered geographical areas at the time of the formation of an agreement or variation in the laws in different states. 

To exemplify, it might so happen that the agreement is not enforceable in one state for not being ratified or has ceased to have effect after expiry or it may happen that one of the parties has been relying on a document that is not actually an agreement between the concerned states but merely a document of historical importance. 

In the Libya Chad case (discussed later), ICJ has made it clear that the will of the states is an important factor in determining the territorial boundaries. Therefore, the agreements (which represent the will of the states) are of utmost importance while examining the boundary disputes. Therefore, parties should negotiate diligently while forming agreements so it does not lead to any confusion at a future time. 

The usual approach of ICJ in resolving boundary disputes can be categorized into two. The first approach of the Court is to see the existence of a boundary agreement. The second relates to examining if this existing boundary agreement is valid or not. These two important trends showcased by the International Court of Justice helps in determining its jurisprudence in boundary and territorial disputes. All such important judgments of ICJ are discussed hereafter based on these approaches.

Important cases by the International Court of Justice

Case of state consent between Libya and Chad (1994)

The Libya Chad case is a landmark judgment of ICJ in the context of territorial disputes. In this case, it was held, “the fixing of a frontier depends on the will of the sovereign States directly concerned”. Here, Libya had been using a barren land on the boundary of Libya and Chad for defense training. Chad objected to the same, claiming the land to be part of its territorial sovereignty. The matter was presented before ICJ. ICJ relied on the Treaty of Friendship and Good Neighborliness agreed between France and Libya which determined the boundaries of states for just twenty years which was later terminated unilaterally. The Court held such boundaries to be permanently based on different international instruments as well as the treaty.  It held that the treaty should be considered to declare the boundary as a permanent frontier. Moreover, it was of the view that the term of a boundary is not dependent on the term of the agreement and would have an effect even after the termination of the agreement.

Validity of Arbitration Award by the UK between Qatar and Bahrain (1994)

This dispute between Qatar and Bahrain was one of its types. In this, the two states saddled the responsibility of delimitation to the United Kingdom to settle their territorial dispute in regards to sovereignty over the Hawar Islands. The UK held that Bahrain had a right over those islands based on the previous rulings and authorization. Qatar approached ICJ contending lack of consent on its part for handling the dispute to the UK. ICJ held that though the British decision was not an arbitral award yet it upheld its decision since it could settle the dispute and was hence binding on both parties. Though the judgment has been criticized, for the reason that it did not examine whether one of the states to the dispute had given consent but rather, it merely showed reluctance to hold such decision invalid that has been evident in many other cases.

Existence of a Boundary Agreement between Cameroon and Nigeria (1998)

Cameroon v. Nigeria (1998) is a boundary dispute case between the two states based on the Maroua Declaration which was a maritime boundary agreement between the two. It was contended by Nigeria that the agreement was not binding since it had not ratified it by then and was merely signed by the head of the state. The International Court of Justice rejected this contention and held that the agreement was enforceable. It held that it was on the states to decide to follow the process that they wish to adopt to make such a treaty enforceable in their municipal system. However, it was binding under international law since the time the two states signed the treaty, irrespective of the date of ratification. Even the text of the treaty did not contemplate any clause for ratification, thus ICJ held the treaty to be binding on both states.

Maritime Boundary Dispute between Botswana and Namibia (1999)

The case of Botswana and Namibia relates to the exercise of territorial sovereignty over Kasikili/Sedudu Island. The concerning issue was to identify the direction of the main channel, which Botswana contended to be north, and Namibia contending it to be south. The ICJ itself took cognizance to identify the main channel which was the north and thus, Botswana had a title over it. Further, Namibia’s contention that its predecessors had title over land was also rejected by the Court. The Court found that Namibia was allowed to use the land exclusively for agricultural purposes in certain seasons and they did not acquire a title or territorial sovereignty over the land. As stated earlier, state consent is very important in the delimitation of territories. This can be reflected truly in this case where there was no consent on part of Botswana to give territorial sovereignty to Namibia in respect to the island in question but to just use it for certain state functions. Thus, ICJ always gives due emphasis to the consent of parties whether such consent is reflected through boundary agreements or their past practices and historical setup.

Non-Boundary Agreement between Indonesia and Malaysia (2001)

Another type of issue that has arisen in the case of boundary disputes is whether any non-boundary agreement could be considered for territorial boundaries. This type of issue arose between the states of Malaysia and Indonesia. Here, Malaysia raised a boundary dispute based on the Exchange of Notes 1907 between the United Kingdom and the United States of America. According to this document, the UK was responsible for the administration of islands and Malaysia, contending to be a successor, claimed a right over such islands. However, ICJ held that such exchange of notes, which was meant for administration purposes could not be considered as a boundary agreement and its contention was thus held invalid. It held that such an administration agreement could not be deemed as a transfer of territory and no inference can be made to the sovereignty of such a disputed island.

Existence of a Tacit Agreement between Nicaragua and Honduras (2007)

This case was yet another maritime boundary dispute between Honduras and Nicaragua wherein Honduras contended that a tacit agreement existed between the two states which were violated by Nicaragua. It relied on fishing practice and policies of parties and their oil concession practice and believed that the 15th parallel created a boundary between the two states. It also stated that its fishermen would rely on this boundary to understand the jurisdiction of Honduras. On the contrary, Nicaragua denied all of these instances as forming part of a maritime boundary agreement. ICJ held that all these instances lasted for a short period and thus, it did not give effect to a permanently binding agreement between the states to follow the 15th parallel as their boundary. It specified that such tacit agreements which form a de facto boundary agreement could only have a temporary effect and cannot last forever. Thus, the Court held that such a tacit agreement could not create a legally binding boundary agreement between the two states.

Validity of Boundary Agreement concluded between Nicaragua and Colombia (2007)

This case relates to a territorial dispute between Nicaragua and Colombia for territorial sovereignty over some islands. The concerned treaty was the 1928 Treaty between the two states which delimited the territory. Further, parties also had been a part of the 1948 Pact of Bogota. Nicaragua contended that the treaty was invalid due to a breach by Colombia. The Court held that Nicaragua did not make any reservations before signing the 1948 Pact. Moreover, the 1928 Treaty was good even in 1948 when the Pact was signed. Thus, it was of the view that the 1928 Treaty between the parties was valid and the dispute was settled by provisions of that treaty itself.

ICJ even applied the principle of ‘objectivization of boundary treaties’ i.e. the Court ratified the delimitation of territories by valid agreements between parties even when such agreement has been terminated. It was of the view that any breach by a state would not lead to the termination of a treaty. Lastly, it stated, “The Court recalls that it is a principle of international law that a territorial regime established by treaty ‘achieves a permanence which the treaty itself does not necessarily enjoy’ and the continued existence of that regime is not dependent upon the continuing life of the treaty under which the regime is agreed.”

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Territorial Dispute based on the letter between Malaysia and Singapore (2008)

In this case, the dispute related to an island named Pedra Branca where a lighthouse had been constructed by the United Kingdom. Through a letter, the Sultan of Johor expressed his positive reply for the construction of a lighthouse to the British Governor (of East India Company), who took this reply as consent for the cession of the territory. Thus, Malaysia, being a successor, claimed its rights on this territory. The ICJ negated his contention by holding that, “any transfer of title on the basis of the conduct of the parties must be manifestly clear and without any doubt, in order to preserve the stability and certainty of sovereignty.” The Court was of the view that these letters did not show that the titleholder was giving his unambiguous consent for the cession of the island which is why it cannot be held that a valid treaty existed which provided for the transfer of such territory.

Validity of Boundary Agreement between Costa Rica and Nicaragua (2009)

In this case, Cuadra–Lizano Communiqué was agreed between Nicaragua and Costa Rica as a result of which the latter could navigate the river under certain conditions. Later, Nicaragua held this Communiqué to have no legal effect. Costa Rica approached ICJ with the contention that Nicaragua breached navigational rights under the Treaty of Limits 1858 which has a connection with the Communiqué. ICJ observed that the Communiqué was a part of a former agreement between the two states and was not linked with the 1858 Treaty. Therefore, though an agreement existed yet it was held to be not valid since it had no provision for navigational rights and a different agreement provided for the same.


It is indeed true that state consent is one of the crucial factors in the determination and delimitation of boundaries. This state consent can be reflected in different ways such as the previous customary practice of the parties or through the boundary agreements. A certain pattern can also be observed in the ICJ cases where it has emphasized the existence of boundary agreements. In case an agreement exists, it also determines its validity. From the above-cited cases, it can be inferred that the ICJ is often reluctant in nullifying the validity of the boundary agreements. One probable reason for the same might be that such agreement represents the consent of state parties to enter into such an agreement or compromise and hence, the Court is not willing to declare it void.

Lastly, the role of the International Court of Justice is commendable in solving the complex and technical boundary disputes between different states wherein it goes to the extent of even examining the scientific and geographical technicalities of boundaries to reach the correct conclusion. It helps a lawful and genuine state party to gain territorial sovereignty over such territory since such title over a territory is based on both factual as well as legal implications. 


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