Customary international law is defined by Talmon as an aspect of the international law that is based on principles of customs.1 It is one of the primary sources of law used at the International Criminal Court and many other member states of the United Nations. It is often used alongside treaties and general principles of the law.2 Many nations around the world have codified the customary international law to fit the local factors. However, the codification is not meant to dilute or misrepresent the law. At the International Criminal Court, the customary international law epitomizes the need to have a uniform legal framework that can define the relationship between countries and parties at an international level. In each of the member states, the law enables the countries to have a legal framework that can make it easy for local entities to operate in a legal environment that can be defined based on international laws. Pellet says that even countries that have embraced dictatorial regimes such as Russia have elements of customary international law.3 In this paper, the primary goal is to look at the constitutive elements of customary international law.
Constitutive Elements of Customary International Law
According to Pellet, some of the landmark rulings made by the International Criminal Court have been questioned by legal scholars and human rights group who argue that sometimes it deviates from the principles of customary law.4 Others argue that sometimes the law is often applied selectively both at national and international levels, especially when handling the rich and powerful. It is necessary to analyze component elements of customary international law to understand the justifications of some of the decisions that are often made in local and international courts. The following are the fundamental constitutive elements of the customary law:
One of the primary constitutive elements of customary international law is the practice of the states.5 Each state may come up with policies meant to regulate the relationship of entities based on emerging issues. It is always the role of the legislative assemblies to come up with policies meant to improve relationships, address ambiguities, and inadequacies of the existing laws, and to clarify issues that make the work of the legal system simple and easy to understand. These policies become part of the law of the country that defines actions taken by the court when resolving disputes. The practice of the state should be general and consistent and must be the state’s sense of legal obligation.6 It may be necessary to use such policies at the international level, where a state’s legal framework may not be legally binding to some of the parties. Noora explains that when it is used at the International Criminal Court, there will be a need for the prosecution of the defence attorneys to satisfy the court that “this custom has become so established as to be legally binding on the other party.”7 It should be clarified to the court why such a custom, used in one country, should be used to define the ruling of a judge at the Hague-based court.
Municipal Acts as Practice
Noora states that municipal acts and judicial decisions may become an element of customary international law if their focus is to address a problem of international law.8 These municipal acts and judgments made by the municipal courts may not be legally binding to the state outside the jurisdiction of the municipality. However, sometimes these judgments or acts address contradictions or ambiguity of the international laws practised within the country. One of the primary challenges when using these acts and judgments as the custom-creating practice is that they are often developed for the domestic sphere. For instance, a country that is strictly governed under Islamic laws may make some adjustments to the international laws at the municipal to avoid contradictions with local beliefs and practices. The municipal council may come up with laws or local courts may set a precedent that is to be legally binding when making future cases. However, it may be difficult to apply such laws and policies when handling an issue at the international level where one of the parties is an American or a European because the law may not be binding on them. For the municipal acts and precedents to achieve extraterritorial application, it is necessary to justify its relevance to all the parties involved in the case. If the bench is convinced and it is used to define a judgment of the court, it may form a precedent, which may be followed in similar cases.
Treaties as Practice
Treaties are a common constitutive element of customary international law. Knoops argues that they are often classified as part of state practice.9 A treaty signed between two or more states may be binding to the parties, if it was drafted within the confines of the local and international law, and may constitute elements of customary international law. The parties will be expected to respect the treaties as long as they remain in force. According to Kriangsak, the International Law Commission developed a guide, the ILC Guide to Practice on Reservations to Treaties, that define when and how such treaties should be applied at an international level.10 Although treaties form fundamental principles that define decisions made by the ICC and other international tribunals, sometimes questions arise about their legality. One of the treaties that have been subjected to criticism about its relevance in modern society is Lake Victoria and the Nile Water Treaty.11
The treaty, which was signed in 1929 when all the East African nations, except Ethiopia, were under colonial rule, gives Egypt veto powers when any of the members of the Nile watershed (Kenya, Tanzania, Ethiopia, Uganda, Sudan, South Sudan, Rwanda, and Burundi) plans to undertake a large-scale project that may affect the flow of water to Egypt12. In a nutshell, the treaty grants Egypt the power to define how each of these countries can use their freshwater sources. The interest of Egypt is protected, but the same cannot be said about the member states. The fact that it was signed when these countries were under colonialism is a major issue that has been raising contention. The treaty has made it almost impossible for the affected members to use this important resource effectively. Such treaties that clearly demonstrate a lack of fairness have been subject to debate as constitutive elements of customary law. However, many other treaties have been fairly used in the international courts and tribunals.
Custom-creating practices may also constitute elements of customary laws. Marchuk explains that some common practices form patterns that make it possible to develop rules of conduct that may eventually become obligatory.13 Islamic finance did not exist a few decades ago. However, when the Dubai Islamic Bank was created in 1975 as the first Islamic financial institution, it started developing policies that were to define its operations. Many financial institutions started embracing the new policy that focused on providing financial products in strict adherence to Quran teachings. The popularity of these principles and their adherence to the people of specific faith all over the world have made them popular. As such, some of their principles have become part of the customary international law.
When a conflict arises between parties that follow these banking principles, it may be necessary to observe the policies as defined in the Quran. Marchuk warns that custom-creating practices can only be applicable at the international level if parties to the dispute agreed to follow specific terms as outlined in the customs.14 For instance, a contract between an Islamic bank and an international company should define the principles upon which it is based. It must be stated in clear terms if Islamic principles will be used in defining the agreements. If such clarifications are not made, the international tribunal may be forced to analyze the agreement to determine if any of the clauses elucidate the need to use the local customs. In case such clarifications are missing, the court will be forced to avoid such local customs when making its judgment.
The uniform practice is a common constitutive element of customary international law. Gardiner explains that when a nation pushes forward a claim and behave inconsistency with the claim and other nations consent to or tolerate such conduct, and most preferably starts behaving in a manner consistent with the claim, then it is believed to be a common practice.15 A case in point is Norway’s decision to adopt a straight base-lines method to delimit the territorial sea for its fishing industry. Many other nations started embracing the new practice instead of questioning the approach that Norway used to expand its sea territory for the purpose of improving its fishing industry. Several years later when the United Kingdom disputed the approach at the International Court of Justice (ICJ) in the case United Kingdom v Norway, popularly known as the Fisheries Case, the court ruled that actions taken by Norway were consistent with the international customary laws.16 The presiding judges ruled that the practice had become a common practice in many countries, although it was started by Norway. The fact that states did not object this claim immediately it was put forward by Norway, and instead practised it in ways that benefited them, was an indication that they considered it applicable. As such, the claim that was put forward at the International Court of Justice was effectively rejected.
General practice, also known as extensive practice, is defined by Fleck as that which “embraces the actions of all those States which are in a position to participate in that practise or have an interest in the subject matter.”17 For instance, states with maritime borders may embrace a standard practice that makes it possible to use the maritime resources in a justifiable way without unnecessarily interfering with other states. When these practices become common and generally acceptable within a given region, then it will be construed that the parties have adopted them and they will become constitutive elements of customary laws. In the Germany v Denmark and the Netherlands, generally known as The North Sea Continental Shelf case, the judges at the International Court of Justice were presented with a case that involved fair usage of resources in the maritime borders of Denmark, Germany, and the Netherlands.18
Germany contested the use of equidistance rule in defining the sea border. It claimed that the North Sea coastline of Denmark and the Netherlands was convex in shape while its own was concave. Using the equidistance method would give the two countries an unfair advantage of access to sea resources, especially oil and fishing grounds, at its expense. The decision made by the court was a clear indication that sometimes the general practice may be overlooked in case there is a glaring injustice that it may commit if it is followed strictly. In the ruling, the judges instructed the parties to engage in a negotiation so that the raised issues could be addressed. The ruling demonstrated that law has no cure for some of these disputes and that the best approach is to embrace negotiation among the affected nations. It is important to note that the decision was not based on the de minimis non-curate lex concept because the issue at hand was of serious magnitude.
Opinio Juris Sive Necessitatis
It is the belief that in some instances a state may take an action because of a legal obligation. The Latin phrase loosely translates into English as ‘an opinion of law or necessity19. The concept is often used by the defence attorneys when describing aggressive actions of their defendants. However, the usage of this concept has been considered subjective both domestically and at an international level. When one is physically attacked, he has the legal right to defend self-using equal or greater force for the sake of survival. If the attacker perishes or is badly harmed in the process, the self-defence principle will be used as the source of the law that justifies such an action. Similarly, when a country is attacked by another country, it will be within the legal space to launch a counterattack to destroy the enemy, even if that involves killing innocent people of that country. This principle justified the United States invasion of Afghanistan. The al Qaeda operatives, led by Osama bin Laden, had planned and successfully implemented an attack on the United States. About 3000 people were killed in the attack and properties worth billions of dollars destroyed in the process20. It was established that the terrorists were operating from Afghanistan where they had the support of the government. The attack gave the United States a justification to attack the government of Afghanistan in pursuit of the criminals. Other important constitutive elements of customary international law include constant practice and transformation of usage into law.
The constitutive elements of customary international law define the sources of law used in the International Court of Justice and tribunals. These sources of law provide a justification for some of the decisions that are made by some countries in the international arena. The decision of the United States’ government to execute a military assault on a premise that was used by Osama bin Laden and the family without consulting the Pakistani government was based on opinion juris sive necessitatis. Such decisions often seem controversial but when they are based on any of the elements of customary international law, they may be justified in the International Court of Justice. Understanding these elements helps in defining the source of laws used in international courts and tribunals.
ALAIN Pellet, ‘The ILC Guide to Practice on Reservations to Treaties: A General Presentation by the Special Rapporteur’ (2013) 24 EJIL 4, 1061.
Arajärvi Noora, The Changing Nature of Customary International Law: Methods of Interpreting Criminal Tribunals (Taylor & Francis Group 2014).
Brölmann and Yannick Radi, Research Handbook on the Theory and Practice of International Lawmaking (Cheltenham: Edward Elgar Publishing 2016).
Dieter Fleck, The Handbook of the International Law of Military Operations (Oxford University Press 2016).
The Germany v Denmark and the Netherlands (1969) ICJ 149 (1969) 3 ICGJ 150.
Iryna Marchuk, The Fundamental Concept of Crime in International Criminal Law: A Comparative Law Analysis (Springer 2014).
Kittichaisaree Kriangsak, Public International Law of Cyberspace (Springer 2017).
Knoops Geert-Jan, Mens Rea at the International Criminal Court (BRILL 2016).
Martin Reichard, The Eu-Nato Relationship: A Legal and Political Perspective (Taylor and Francis 2016).
Richard Gardiner Treaty Interpretation (Oxford University Press 2015).
STEFAN Talmon, ‘Determining Customary International Law: The ICJ’s Methodology between Induction, Deduction and Assertion’ (2015) 26 EJIL 2, 417.
The United Kingdom v Norway (1951) ICJ 3 (1951) 58 CIJ 51.
- STEFAN Talmon, ‘Determining Customary International Law: The ICJ’s Methodology between Induction, Deduction and Assertion’ (2015) 26 EJIL 2, 417.
- Ibid 420.
- Alain Pellet, ‘The ILC Guide to Practice on Reservations to Treaties: A General Presentation by the Special Rapporteur’ (2013) 24 EJIL 4, 1061.
- Ibid 1063.
- Catherine Brölmann and Yannick Radi, Research Handbook on the Theory and Practice of International Lawmaking (Cheltenham: Edward Elgar Publishing 2016) 86.
- Arajärvi Noora, The Changing Nature of Customary International Law: Methods of Interpreting Criminal Tribunals (Taylor & Francis Group 2014) 45.
- Ibid 57.
- Ibid 89.
- Knoops Geert-Jan, Mens Rea at the International Criminal Court (BRILL 2016) 68.
- Kittichaisaree Kriangsak, Public International Law of Cyberspace (Springer 2017) 112.
- Ibid 59.
- Iryna Marchuk, The Fundamental Concept of Crime in International Criminal Law: A Comparative Law Analysis (Springer 2014) 33.
- Ibid 62.
- Ibid 27.
- Richard Gardiner Treaty Interpretation (Oxford University Press 2015) 54.
- The United Kingdom v Norway (1951) ICJ 3 (1951) 58 CIJ 51.
- Dieter Fleck, The Handbook of the International Law of Military Operations (Oxford University Press 2016). 65.
- The Germany v Denmark and the Netherlands (1969) ICJ 149 (1969) 3 ICGJ 150.
- Martin Reichard, The Eu-Nato Relationship: A Legal and Political Perspective (Taylor and Francis 2016) 114.
- Ibid 78.