African Center for international arbitration

catalogue
1、 Introduction
2、 Default in International Law Theory
3、 Default recognition in international judicial practice
4、 The legal effect of default in international judicial practice
5、 Conclusion

                                                                                                   3、 Default recognition in international judicial practice
        Although default is an important concept in international law theory, its recognition rules and legal effects have not been clarified at the theoretical level, that is, how to determine that a state's behavior constitutes default, and what legal effects a state's default will produce. The practice of judicial institutions has played a crucial role in this regard. Through the continuous accumulation of dispute resolution practices in judicial institutions, especially in resolving territorial sovereignty and maritime delimitation disputes, the default recognition rules, constituent elements, and their legal effects have gradually been determined and clarified. The following text reads and analyzes 18 cases involving default from 1909 to 2008.
In practice, there are many reasons why the state remains silent or does not object. As Gerald Fitzmaurice pointed out, not protesting does not necessarily or always imply acquiescence, but rather depends on whether the specific situation requires opposition, as not opposing at this point implies agreement or inference of acquiescence. Therefore, only silence that meets the conditions, namely "qualified silence", can produce specific legal effects, which some scholars refer to as "normative acquiescence" based on the principle of good faith in international law. In practice, international judicial institutions, based on the specific circumstances of individual cases, mainly determine whether the relevant actions of a country constitute default from the following three aspects.
     （一） The state's silence or lack of opposition must last for a period of time
       The duration of time plays a crucial role in default identification. On the one hand, it can ensure that the country has time or opportunity to respond. The longer the duration, and the country remains silent or does not object, the easier it is to infer the country's acquiescence. In the 1951 Fisheries case (UK v. Norway), the International Court of Justice held that Norway had consistently and uninterrupted applied its special territorial sea baseline system from 1869 until the dispute arose, and had never faced opposition or resistance from the international community, including the UK, for a long time. Therefore, the UK's refusal to object for over 60 years could constitute a tacit acceptance of Norwegian practice. The 1962 case of Preah Vihear Monastery (Cambodia v. Thailand) further highlighted the importance of time in determining default. In this case, the International Court of Justice held that Thailand had been aware of the existence of the Annex 1 map published by the Mixed Commission since 1908, and that the map was also publicly available and made public to other countries. If Thailand believes that the map is inaccurate, it should raise objections in a timely manner, but Thailand did not raise objections until 1958, so it should be considered as having assumed the validity of the map. On the other hand, the long-term historical development process has also created a stable international order and situation. Unless a country explicitly opposes or protests, this stable situation must be respected and maintained, that is, the principle of "quiet non move". For example, in the jurisdiction judgment of the 2007 Caribbean Sea Territory and Maritime Dispute case (Nicaragua v. Colombia), the International Court of Justice also held that Nicaragua had never claimed that the treaty was not binding on it for more than 50 years after its signing in 1928, and therefore, the treaty was valid. However, international law does not specify the duration of this "never claimed" claim, but should be determined based on specific circumstances. Among the 18 cases compiled in Table 1, the longest time recognized as default existence is 137 years, and the shortest time is 6 years.
      （二） The country should have the opportunity or means to know relevant facts
       The state can only respond to situations within its knowledge. Therefore, countries should first ensure that their actions are made public to the international community through various channels. For example, issuing public statements, holding press conferences, conducting domestic legislative, judicial, and law enforcement activities, issuing official documents in various forms such as administrative bulletins, and submitting diplomatic notes provide channels for other countries to understand their own positions and propositions. The non-public behavior implemented by the state cannot constitute default as it cannot be known to other countries. However, this does not require the state to notify other countries of all its sovereign actions, as long as the state discloses them in a reasonable and normal manner and channels without deliberately concealing them. In the 1959 Partial Border Territory Dispute case (Belgium and the Netherlands), the Netherlands advocated for the implementation of national sovereignty actions over disputed territories, including land ownership transfer registration, population registration, marriage and death registration, taxation, and other activities, and never faced any opposition or protest from Belgium. However, the International Court of Justice believes that due to the disputed territory being surrounded by Dutch territory, most of these actions are routine administrative activities carried out by the local Dutch government, making them difficult for Belgium to be aware of. Therefore, Belgium's failure to object cannot constitute acquiescence. From this, it can be seen that a country should maintain high vigilance towards the actions of other countries, especially those of countries with potential or actual disputes with its own country. Once any behavior that harms its own country is discovered, it should respond promptly to fulfill its duty of prudence, otherwise it may put it at a disadvantage. In modern international society, diplomatic relations between countries are becoming increasingly close and normalized, and the channels for obtaining information are becoming more convenient and open, which is particularly important.
In the Fisheries case (UK v. Norway), the UK argued that Norway's baseline system was not made public to it. In this regard, the International Court of Justice has made a classic argument that as a coastal country in the North Sea, Britain has extensive fishing interests in the region and is a maritime power that has traditionally been very concerned about the law of the sea and advocates the principle of maritime freedom. It is impossible to ignore Norway's law of 1869. At the same time, the law immediately triggered the French government to demand an explanation from Norway. In addition, in the 1981 Border Arbitration Case (Dubai and Sharjah), the arbitral tribunal held that even if Sharjah had not implemented sovereignty activities in the disputed area, it must have been aware of the road construction project being carried out in Dubai, as the implementation of the project could be clearly seen from the road connecting Dubai and Sharjah. But Sharjah did not respond to this, which precisely proves that it does not consider the Mazel Peninsula to be a part of its territory. These two cases demonstrate that the actions taken by Norway and Dubai only need to reach a sufficient level of awareness to the UK and Sharjah, without the need to notify each other of their actions. The UK and Sharjah should maintain a high level of attention to the actions of relevant countries. If they believe that the other party's actions infringe on their territorial sovereignty or maritime rights, they should promptly raise objections or protests to demonstrate their own position and attitude.
     （三） The country should and can respond but remain silent
       This is the most important criterion for determining whether it constitutes default. Among them, "should" means that the state has an obligation to object, as pointed out by the International Court of Justice in the Preah Vihear Temple case, if the state should and could have responded but did not act in such a way, this silence means agreement. However, international law does not generally specify under what circumstances and on what grounds a country should object or protest. In normal circumstances, if a treaty stipulates the conditions under which a state should object, such as Article 20, paragraph 5, and Article 45 of the 1969 Vienna Convention on the Law of Treaties, or if a state believes that another state has violated the treaty or customary rules of international law it has signed, or that its actions have harmed or may harm its own interests, then that state should object or protest within a reasonable period of time, otherwise it can be presumed as acquiescence. In the 1909 Grisbadena Arbitration Case (Sweden and Norway), Sweden set up lighthouses and numerous buoys for navigation safety in the Grisbadena area, but Norway never protested against this.
At the same time, the country should also have the ability to respond, which should be determined from both objective and subjective aspects. Objectively speaking, countries are aware and aware of relevant facts, such as violations of treaty obligations by other countries or infringement of their own interests, which is in line with the above requirements for transparency. In subjective terms, the failure of a country to respond is not due to coercion or coercion, but rather based on relevant facts and is the result of its own judgment and decision, which is an expression of its own free will. As for the time frame within which a country should respond, international law does not specify. Of course, an immediate response from the state is the most ideal state, which can promptly block the formation of default. In the 1932 Clayton Island Arbitration case (Mexico v. France), although France had never engaged in any actual occupation of the island from 1858 until the dispute arose, upon learning of Mexico's sovereignty claim, France immediately responded and declared its territorial sovereignty. However, whether the country raises a protest or not may require a reasonable period of careful analysis and judgment. Therefore, if a country fails to respond within a reasonable period of time, it should be considered as constituting default. What is a "reasonable period" should be determined through case analysis based on specific circumstances.
                                                                                                  4、 The legal effect of default in international judicial practice
      （一） The probative role of evidence in general circumstances
         The default is to infer a country's attitude and intention from its silence or inaction, which requires analysis and elaboration of relevant facts and inevitably has a certain degree of subjectivity. It is precisely because of this characteristic that there are judges who have raised objections to the cases mentioned above. But it cannot be denied that default is an important factor that international judicial institutions need to consider when resolving disputes, especially territorial sovereignty and maritime delimitation disputes. In general, international judicial institutions, after drawing conclusions based on other rules such as treaties, the principle of maintaining possession, and the rule of effective possession, then examine the attitudes of other countries in the international community, especially those with interests, to prove, confirm, or reinforce the above conclusions, thus forming a closed loop of argumentation and increasing the persuasiveness of the judgment. Therefore, default is generally used as evidence to prove, confirm, and enhance conclusions drawn from other rules. As McGibben believed, the main function of default is evidential, and its value lies mainly in serving as an acknowledgement of legitimacy and providing an objective and practical standard. D. W. Gregg also advocates that if a country can prove that it has exercised sovereignty over disputed territories, the judgment of judicial institutions may be advantageous in proving that its claims have been accepted by other countries.
In the 1933 case of the Legal Status of East Greenland (Denmark v. Norway), the Permanent International Court of Justice proposed two elements that must be considered in obtaining territorial sovereignty: the first is the intention and willingness to act as a sovereign and the act of exercising territorial sovereignty, and the second is whether other countries have made competitive claims. On the basis of examining Denmark's sovereign actions in different historical stages, the court emphasized the importance of "the absence of competitive claims from other countries", that is, the default attitude of other countries, supplementing and enhancing the legal effectiveness of Denmark's sovereign actions.
In the 2002 Lijitan and Sibatan Sovereignty Dispute case (Indonesia and Malaysia), both countries had very limited acts of sovereignty over the disputed islands. After comparing and measuring, the International Court of Justice found that although Malaysia had carried out a relatively small number of acts, it had a wide variety of types, including legislative, administrative, and quasi judicial activities, which lasted for a considerable period of time and indicated its intention to carry out sovereign acts over the disputed islands. To reinforce this conclusion, the court further pointed out that Indonesia has never opposed or protested against these actions
In the 2007 Territorial and Maritime Dispute case (Nicaragua v. Honduras), the International Court of Justice, after examining a series of effective occupation acts committed by Honduras over the disputed islands, determined that these acts could be regarded as evidence of the country's "intention and will to act as a sovereign" and constituted a "moderate but real" display of power over the disputed islands. On this basis, the court further pointed out that these actions could be considered known to Nicaragua, but did not provoke protests from the country.
In the above judicial practice, the acquiescence of the state serves as evidence to enhance, reinforce or consolidate the conclusions drawn by judicial institutions based on other international legal rules, thus forming a closed loop of argumentation. The role of default as evidence is mainly to examine state behavior and interpret it to confirm the legitimacy of a country's claims. However, this does not mean that the legitimacy of a country's rights depends on the acquiescence of other countries, which only serves to enhance and support a country's claims.
      （二） As a basis for determining rights in certain situations
         The default ultimately boils down to the recognition of the legitimacy of the rights, claims, or specific circumstances of other countries by the state. Although it is expressed as "should be opposed but not opposed" or "should be done but not done", it is essentially an expression of the state's attitude and intention. As pointed out by the Special Chamber of the International Court of Justice in the 1984 Bay of Maine Maritime Delimitation Case (Canada and the United States), acquiescence is equivalent to implied recognition expressed by unilateral acts, which the other party may interpret as consent. From this, it can be seen that although a state has not taken positive actions, silence or inaction itself can constitute an expression of the state's will, and is a recognition of the legitimacy of the actions or circumstances of other countries. Therefore, in some cases, the formation and change of legal relations between countries can be achieved through the acquiescence of one country to the actions of another country. Given the parallel structure of the international community and the principle of national sovereignty equality, determining the rights and obligations between countries must be based on legitimate reasons and basis. Although it is assumed to be a unilateral act of the state and cannot be used as a basis for determining rights alone, if a country remains silent or does not act for a long time in relation to an act committed by another country, especially when such an act may constitute an infringement of its legitimate rights, it can be considered that a new common will has been reached between the country and the other country. The country abandons or changes its previous claim or position, acknowledges the previous claim, position or situation of the other country with its default behavior, and thus forms a new relationship of rights and obligations. In this case, default is a form of expression of the common will of the states and serves as the legal basis for determining the rights and obligations between states. In other words, default provides a mechanism and approach for the formation of new consensus in the interaction between countries, thereby forming new rights and obligations and achieving changes in legal relationships between countries. In this sense, default can be seen as a "shock absorber" to promote peaceful changes in international relations, ultimately achieving a smooth transition of the international order. Therefore, default can effectively indicate how the legal relationships between countries are changed through mutual interaction.
The relevant judicial practice has also confirmed the default role, and the most typical case is the case of Preah Vihear Monastery (Cambodia v. Thailand). In this case, according to the border treaty signed between France and Thailand (Siam) in 1904, the boundary line between the two countries in the eastern section of the Biandan Mountains is the watershed line of the mountains, and the Preah Vihear Monastery is located north of the watershed line and should belong to Thailand. However, according to the map published by the Mixed Committee established under the treaty, namely the map in Annex 1, the temple is designated on the Cambodian side, which clearly contradicts the provisions of the 1904 treaty. In this regard, the International Court of Justice believes that although the map is not legally binding, after its production, it has been widely made public to important countries and major geographic surveying and mapping organizations, including Siam. If Siam believes that the map is incorrect, it should object or question its correctness within a reasonable period of time. However, Siam has not taken any action at that time and for a long time thereafter, so it must be considered that it has tacitly agreed and cannot object or question the map anymore. In this case, although there were clear provisions in the 1904 treaty, Thailand's long-standing acquiescence can be seen as a new agreement reached between the country and Cambodia on the sovereignty of Preah Vihear Monastery.
Similarly, in the 1992 Land, Island, and Maritime Boundary Dispute case (El Salvador and Honduras), the Special Chamber of the International Court of Justice also believed that the acquiescence of a state could alter the boundaries delineated under the principle of "maintaining possession". When discussing the issue of key dates, the court pointed out that the boundaries delineated based on the principle of "maintaining possession" can be modified by rulings and treaties after the independence of the parties, or when there is sufficient evidence to prove that the parties have actually changed the original boundaries through other means, such as acquiescence or recognition. When determining the first section of the land boundary, the Special Chamber also believes that the legal effect of the principle of "maintaining possession" is not to permanently "freeze" the borders of independent countries, and relevant countries can still change the original boundaries through agreements, certain actions, or acquiescence.
The 2002 Land and Maritime Border Dispute case (Cameroon v. Nigeria) once again confirmed the role of default. When determining the sovereignty of disputed territories in the Lake Chad region, the International Court of Justice pointed out that since Cameroon already enjoys existing rights in the region, it is necessary to determine whether Cameroon agrees to transfer its rights to Nigeria. Even if Cameroon's sovereignty in the region has been established, if there is evidence to prove that it has tacitly transferred sovereignty to Nigeria, then it can be considered that the sovereignty of the region has changed.
In the 2008 sovereignty dispute over Shirakaki Island, Nakayama Island, and Nanato Island (Malaysia and Singapore), the International Court of Justice elaborated on the international legal rules for the transfer of territorial sovereignty in examining the territorial sovereignty of Shirakaki Island after 1844. The International Court of Justice believes that this change of sovereignty can be achieved through an agreement, which can be either a treaty or an implied action derived from the actions of all parties. International law does not require any special form, but emphasizes the common intention of the parties involved. Therefore, in some cases, if a country carries out a sovereign act over disputed territory and no other country protests against it, it will constitute acquiescence, forming a state agreement and leading to the transfer of territorial sovereignty.
Nevertheless, caution must be exercised regarding the legal effects that arise from default. Default is a way for a country to express its attitude and position through passive inaction, which is a negative concept that must be examined in the specific context of interaction between countries. The default as the basis for determining rights has the effect of changing the original legal order, therefore, it is necessary to emphasize the will and attitude of the state that interests are damaged in the newly formed legal order. In this sense, acquiescence is a way to achieve changes in the relationship between state rights and obligations, and to establish it on a stable basis of national consensus. It not only avoids questioning and opposing the new legal order and relationship by the state recognized as acquiescence, but also protects the trust interests of the state claiming the existence of acquiescence.
       （三） When the conditions are met, it can have a legal effect of prohibiting estoppel
          The prohibition of estoppel is a principle in common law that has been introduced into international law as one of the "general legal principles" referred to in Article 38 (1) (3) of the Statute, and has been repeatedly confirmed by international judicial practice. In the Preah Vihear Temple case, Judge Alfaro pointed out in a separate opinion that the prohibition of estoppel is a general legal principle frequently applied by the International Court of Justice under Article 38 of the Statute. Similar to default, the basis for the emergence and existence of estoppel is also the principle of good faith, consistency, and the maintenance of international order and stability in state relations in international law. Its purpose is to protect the trust interests arising from it when a state acts based on trust in the actions of another state, to ensure that such interests are not harmed or threatened by the inconsistent words and actions of another state in the future. The International Court of Justice clearly stated in the North Sea Continental Shelf case that a state that prohibits estoppel must demonstrate that it takes action based on the declaration of another state. Therefore, the prohibition of estoppel requires that the attitude and position adopted by the state must be consistent, in order to protect the trust interests of other countries acting on this basis. As McGibben believed, the prohibition of estoppel requires a state to maintain a consistent attitude towards a certain fact or legal situation, which is based on maintaining the stability of international relations and the predictability of state behavior.
In judicial practice, the prohibition of estoppel and acquiescence often apply simultaneously to exclude competitive claims made by other countries. Therefore, some scholars believe that the difference between default and estoppel in application is very vague. In fact, acquiescence and estoppel play a role in different stages and scopes. As a way for countries to express their attitudes and positions, as well as interact with each other, default can become one of the prerequisites for the application of estoppel, and estoppel is one of the legal effects produced by default. As Schwarzenegger believes, in situations where the principle of good faith requires relevant countries to take positive actions to preserve their right to freedom of action, default will have the effect of prohibiting estoppel. If other countries rely on their default to act, it will generate trust interests, and the country has an obligation not to change its attitude and position in the future, in order to cause losses to the country that enjoys trust interests, or to benefit itself. However, as pointed out by Malcolm N. Shaw, whether silence can have the effect of prohibiting estoppel largely depends on the specific environment and conditions, especially the openness of the situation, the duration of silence in response to this situation, and the types of reasonable actions taken in the international community to safeguard legitimate interests, and estoppel cannot be easily inferred. Therefore, the default that can produce the effect of estoppel must meet certain conditions, in other words, not all defaults produce this effect. These conditions should include the following aspects. Firstly, a country is aware of the long-standing rights and attitudes that conflict with its own interests and should object or protest against the use of estoppel, but remains silent on this matter. It is precisely this kind of "should be done but not done" that constitutes a clear expression of the country, while the long-term absence of opposition or protest indicates that the country's expression is consistent. Secondly, the country that cites the prohibition of estoppel has reasonable grounds to rely on its default behavior, thereby forming a trust interest. Thirdly, the clear and consistent representations made before the change of state-owned enterprise plans should be assumed. Fourthly, a country that cites the prohibition of estoppel may suffer losses or gain benefits from a change in the attitude of the defaulting country. Even if there is a change in the attitude of the default country, but it does not cause the above consequences, it cannot constitute a estoppel. This will distinguish between default and estoppel.
The legal effect of default leading to the prohibition of estoppel has been repeatedly confirmed by international judicial practice. In the Fisheries case (UK v. Norway), the International Court of Justice pointed out that the general tolerance of foreign countries towards Norwegian practices is an indisputable fact, and the UK government has never questioned this for a period of 60 years. The court subsequently concluded that the public nature of the relevant facts, the location of the UK in the North Sea and its interests in the region, as well as the country's long-standing inaction, all ensured that Norway could apply the baseline system to the UK. In addition, until the dispute arose, Norway's baseline delineation method had been "solidified" over a sustained and sufficiently long period of time, and the attitudes of other countries towards this also proved that this method did not violate international law. Here, the International Court of Justice did not mention the prohibition of estoppel, but from the perspective of the judgment reasoning, the court has actually recognized that as a coastal country with significant interests in the North Sea, the long-term default of the baseline system applied by the United Kingdom and even the international community to Norway has formed a stable trust interest in Norway.
        In the case of Preah Vihear Monastery (Cambodia v. Thailand), after determining that Thailand had already acknowledged Cambodia's sovereignty over the temple, the International Court of Justice clearly stated that for 50 years, Thailand had enjoyed the benefits brought by the 1904 Treaty, and Cambodia also believed that Thailand had accepted the Treaty. Although the International Court of Justice did not explicitly mention the prohibition of estoppel, it has actually applied this principle and has become one of the reasons and basis for the final judgment. The legal effect of default leading to the prohibition of estoppel was directly and clearly confirmed and proven in the 2015 Chagos Marine Protected Area Arbitration Case (Mauritius v. United Kingdom). In this case, the arbitral tribunal provided a clearer explanation of the conditions for the application of estoppel, namely that the state may make a clear and unanimous expression through speech, behavior, or silence.
                                                                                                                     5、 Conclusion
       Default is an important concept in international law, which expresses consent through the passive inaction of a state. Some important issues and concepts in international law are closely related to default. From the perspective of default function, it is of great significance for the recognition of customary international law rules, the formation, development, and changes of rights and obligations between states, and the legal effect of estoppel. From this, it can be seen that default not only drives the continuous transformation of international rules, but also helps to achieve changes in the rights and obligations between countries, in order to better maintain the stability of international relations and order, and maintain fairness and justice.