Sources of International Law Explained

Sources of International Law

 

By ‘sources of international law’, I mean the origins or places from which the rules and principles of international law are derived.

And these sources help establish the legal framework that governs the relations between countries.

You must be thinking that why study about the sources of international law, why not simply study what international law is?

Why take all this trouble?

It is because the sources of international law collectively shape the rules and principles that guide the behavior of nations in the international community.

And by understanding these sources, you will gain insight into how international law is formed, applied, and adapted to address global challenges and promote cooperation among countries.

Here, the most important legal provision you are supposed to remember is Article 38 of the Statute of the International Court of Justice (ICJ). It provides for six different sources of international law that are to be applied by the courts while deciding a dispute. Those six sources are: -

custom, treaties, general principles of law, judicial decisions, juristic writings and equity.

 

Custom

 

It is like the unwritten rules that countries follow because they've been doing it for a very long time, and everyone believes that it is the right thing to do.

For example, most countries agree that it's not okay to attack other countries without a good reason. This understanding has become a custom that everyone expects and follows. Even though there might not be a specific written agreement or law, it's understood that attacking another country without a good reason is not permissible in international law.

Malcolm Shaw, a famous writer, defines custom as a long established and commonly adopted practice that has acquired the force of law.

Thus, even if something is not a law in the traditional sense of the term, still if it is treated or equated with a law, then it could be said that it has acquired the force of law.

Basically, there are two pre-conditions that need to be met before a custom becomes a valid custom in international law, State Practice and Opinio Juris. These reflect the manner in which states behave and incorporate the custom into their own law. To know more about State Practice and Opinio Juris, watch my earlier episode the link for which has been provided in the description below.

Now, broadly speaking, there are three types of customs, general, regional and local.

General Customs are followed universally in most places and jurisdictions.

Regional Customs are rules that bind only a particular group of states in a particular region. For example, North America may have its own Regional Customs distinct from South America or Asia.

Local Customs are rules that bind only a smaller number of states have in a limited geographical area like India Pakistan and Sri Lanka may have a local custom that may not be followed anywhere else.

Lastly, the importance of custom as a source of law has been discussed in various cases such as the Lotus Case and Nicaragua v. United States.

 

Treaty

 

It has been defined in Article 2 (a) of the Vienna Convention of Law of Treaties, 1969 (VCLT) as an international agreement concluded between States in written form and governed by international law.

Thus essentially, a treaty is a written agreement between two or more countries and is subjected to various principles of International Law.

The nomenclature of treaties is immaterial, and it may be called an Agreement or a Pact or a Convention or a Protocol or a Charter or any other similar term.

You should also know that a treaty between two nations is called a Bilateral Treaty and a treaty between more than two nations is called a multilateral treaty.

Sometimes even non-state actors may also become part of a treaty. A good example is Paris Agreement on Climate Change where Civil Society Organizations such as the Climate Action Network (CAN) are a part of it.

Here, you must also know that all the treaties must be observed and performed in good faith. This is called the principle of ‘Pacta Sunt Servanda’ that has been provided in Article 26 of VCLT.

There are various examples of treaties such as the Antarctic Treaty of 1959, Patent Law Treaty of 2000, VCLT of 1969, Kyoto Protocol of 1997 etc.

The relevance of treaty as a source of international law has been discussed in the North Sea Continental Shelf Cases.

 

General Principles of Law

 

It is also a term that is hard to define, and simply means general principles that guide different legal systems such as the principle of good faith, doctrine of res judicata, principle of estoppel, doctrine of proportionality and principle of Pacta Sunt Servanda.

General principles of law are regarded as a source of international law because the international law is relatively new and many times issues arise on which is there is no international law whatsoever, in those circumstances, the Court may apply a legal principle that is usually applied in domestic or internal legal systems of countries.

These general principles have been applied in a plethora of cases to fill the uncovered gaps arising in international law from time to time such as the Chorzów Factory case, German Settlers in Poland case, the Corfu Channel case and many others.

 

Judicial Decisions

 

 It means the judgments and orders that are passed by the International Courts in different matters on different points of law.

You should know that Article 38 of ICJ Statute regards ‘judicial decisions’ as a subsidiary means of determining law. Subsidiary means a secondary source of law rather than an actual source of law.

Further, Article 59 of the ICJ Statute states that the decision of the ICJ has no binding force except as between the parties who have submitted themselves to its jurisdiction.

So, if India and Pakistan submit a dispute before the ICJ, the decision of the ICJ would be binding only on India and Pakistan and only for that particular matter. If a similar matter arises in the future, both the countries will again have to file a dispute before the ICJ.

This does not mean that ‘judicial decisions’ are not important. They are still relevant because of the doctrine of precedent according to which courts follow their previous decisions when deciding similar cases, and generally speaking, the Courts do not depart from its settled jurisprudence or precedent unless there are compelling reasons to do so.

Today, various international courts pronounce decisions on different subjects and these decisions form the jurisprudence which will also influence the future decisions of the International Courts.

The importance of Judicial Decisions as source of international law has been discussed in detail in cases like the Genocide Convention Case, the Nottebohm Case and Cameroon v. Nigeria.

 

Juristic or Academic Writings

 

Again, like ‘judicial decisions’, Article 38 regards them as a subsidiary means of determining law and this does not mean that academic writings are irrelevant in international law. The influence of academic writers in the development of international law has been immense.

Scholars such as Gentili, Hugo Grotius, Vattel and Pufendorf were considered as the supreme authorities of their times on International Law.

However, with the rise in the number of international treaties, the significance of academic writings has been reduced to an extent. Nevertheless, good books on international law are still being cited by the lawyers before the courts and whenever a new branch of international law is to be developed, the academic writers play an important role in giving proper shape to it.

Some of the examples of juristic and academic writings are the Oxford Handbook of International Law and the Law of Nations by Emer de Vattel.

 

Equity

 

The sixth and the last source of international law as per Article 38 (2) of ICJ Statute is ‘equity’.

Actually, the term used in Article 38 is ‘ex aequo et bono’ that literally means as per what is equitable and good. It means the body of principles constituting what is fair and right and represents the various values present in a legal system. It includes principles and doctrines such as Rule of Law, Natural Justice, Peaceful Coexistence etc. Honestly, I find the principles of equity to be quite similar to general principles of law. Nevertheless, the ICJ statute has made a distinction. These principles of equity have been applied consistently by the International Courts in cases such as the Rann of Kutch arbitration between India and Pakistan in 1968, North Sea Continental Shelf cases, Legality of the Threat or Use of Nuclear Weapons Advisory Opinion etc.

 

Other Sources of International Law

 

Apart from the just discussed six sources of international law, there are some other sources of international law as well that have not been recognized under Article 38 of the ICJ Statute, yet they are liable to be considered as valid sources of international law. These sources of international law generally evolve in development of new laws and from new interpretations of existing laws. Some examples are: -

UN Security Council Resolutions – These resolutions are considered as binding by virtue of Article 24 and Article 25 of the UN Charter according to which the members of UN must accept and carry out the decisions of the Security Council.

Then Soft Laws such as Codes of Practice of Standards, Recommendations and Guidelines by International Bodies etc. also form as a source of international law in a limited manner. Soft Law basically indicates an instrument or provision that is not a law but its importance within the International System is such that particular attention requires to be paid to it.

Further, Works of International Law Commission and other International Bodies such as UNCITRAL involved in drafting and formulation of law, also act as a source of international law in many cases.

Lastly, Unilateral Acts like Annexation of Crimea by Russia may also give rise to international legal obligations at times and may be considered as a source of international law.