International Law and its Evolution

Synopsis

·       Introduction

·       Internation Law

·       History and Development

1.     Ancient Periods,

2.     Medieval Period,

3.     Modern Period,

4.     19th Century,

5.     20th Century,

6.     Contemporary Period

·       Sources of International Law

·       Theories of International Law

·       Subject of International Law

·       Conclusion.

 

Introduction

International law (Law of Nation) is a system of rules that governs relations between states and other global actors. It helps maintain peace, cooperation, and justice across nations. Hugo Grotius, known as the Father of International Law. Later, Jeremy Bentham coined the term “international law,” shaping the modern legal framework for global relations. Together, their ideas laid the foundation for today’s international legal system.

 

International Law

International law is a set of rules, agreements, and treaties that govern the relationships between countries and other international actors. It outlines the legal responsibilities of states in their interactions with each other and with individuals within their borders. International law covers a wide range of issues, including human rights, international trade, environmental protection, and the use of force. 

According to Hugo Grotius “International Law” means "A system of rules based on natural law, reason, and the consent of nations, governing relations between states in times of peace and war."

According to L. Oppenheim "Law of nations or international law is the name for the body of customary and conventional rules which are considered legally binding by civilized states in their intercourse with each other."

 

History and Development

F Ancient Period:

During the ancient period, early civilizations like Mesopotamia, India, Egypt, China, Greece, and Rome followed certain customs and rules when dealing with other kingdoms. These included making peace treaties, respecting diplomats, following rules during war, and settling disputes through talks or arbitration. For example, the Treaty of Kadesh between Egypt and the Hittites is one of the world’s oldest recorded peace treaties.

In India, Kautilya’s Arthashastra explained how kings should make alliances and follow fair war practices (dharma yuddha). The Romans introduced jus gentium, a law for dealing with foreigners, which later influenced modern international law. Though not written like today’s laws, these early practices formed the base for the development of international law by promoting peace, cooperation, and fairness among states.

 

F Medieval Period:

During the medieval period, international law was influenced mainly by religion, especially the Catholic Church in Europe. There was no clear idea of state sovereignty as we know today. Instead, the concept of a universal Christian community guided international relations. The Church played a major role in settling disputes, and religious leaders acted as mediators.

St. Augustine and St. Thomas Aquinas developed the Just War Theory, which laid down moral rules for starting and conducting war. While international law was not formally developed during this time, the period helped shape ethical foundations and laid the groundwork for future legal systems between states.

 

F Modern Period:

The modern period of international law began after the Treaty of Westphalia in 1648, which established the idea of state sovereignty. This period saw the rise of nation-states and formal diplomacy.

Hugo Grotius, known as the "Father of International Law," played a key role during this time by promoting the idea that even in war, states must follow certain moral and legal rules. Gradually, the number of treaties increased, and international customs became more structured.

 

F 19th Century:

The 19th century was a time of major growth and codification in international law. After the Napoleonic Wars, the Congress of Vienna (1815) brought European powers together to maintain peace and balance.

This period saw the rise of permanent diplomacy, more written treaties, and early international organizations like the International Telegraph Union (1865) and Universal Postal Union (1874). Efforts to make war more humane also began, with agreements like the Geneva Convention (1864) for protecting wounded soldiers.

The Hague Conferences of 1899 and 1907 further developed rules on warfare and peaceful settlement of disputes. Overall, the 19th century laid the groundwork for modern international cooperation and legal order between states.

 

F 20th century:

The 20th century marked a turning point in international law with the creation of global institutions and a focus on peace and human rights. After World War I, the League of Nations was formed in 1919 to prevent future wars, though it later failed. After World War II, the United Nations (UN) was established in 1945, becoming the most important international body for promoting peace, development, and legal cooperation. This century also saw the birth of international human rights law, the Nuremberg and Tokyo Trials for war crimes, and the Geneva Conventions for humanitarian law. Treaties on nuclear weapons, trade (like GATT and WTO), and the environment were introduced. The International Court of Justice (ICJ) and later the International Criminal Court (ICC) were established to enforce legal rules. Overall, the 20th century made international law more formal, organized, and global in reach.

 

F Contemporary Period:

The contemporary period, mainly covering the 21st century, shows how international law continues to grow and adapt to modern global challenges. Today, international law deals not only with traditional issues like war and treaties but also with climate change, cybersecurity, terrorism, space law, and global pandemics.

International organizations, NGOs, multinational companies, and even individuals are recognized in the legal system. Courts like the International Criminal Court (ICC) now hold individuals accountable for serious crimes like genocide and war crimes. International cooperation is more important than ever, and laws are being developed to address global problems that affect all countries. Though enforcement remains a challenge, international law today plays a vital role in promoting peace, justice, sustainability, and human rights around the world.

 

Sources of International Law

According to Article 38 (1) of ICJ

a)     Convention

b)     Custom

c)     General Principle of Law

d)     Judicial Decision.

 

F International Conventions (Treaties):

International conventions, also called treaties, are formal written agreements between two or more countries that create legal obligations under international law. They are the most important and widely used source of international law today. Treaties can cover a wide range of topics such as trade, human rights, environment, or peace. Once a country signs and ratifies a treaty, it is legally bound to follow its rules.

 

F International custom:

International custom is a major source of international law that comes from the long-standing practices and behaviour of states followed over time. For a custom to become law, it must be widely accepted and consistently practiced by countries, and there must be a belief that such practice is legally required, this belief is called opinio juris. Customs are unwritten rules, but they are still legally binding.

 

F General Principles of Law:

General principles of law are basic legal ideas and rules that are common to most national legal systems. These principles are used in international law when treaties or customs do not provide an answer. They help ensure fairness, justice, and logical reasoning in legal decisions.

a)     Good faith,

b)     Equity,

c)     Res judicata,

d)     Pacta Sunt Servanda, etc...

F Judicial Decisions:

Judicial decisions refer to the past rulings and judgments made by international courts and tribunals, such as the International Court of Justice (ICJ), the International Criminal Court (ICC), and arbitration tribunals. While these decisions are not binding on other cases, they are used as guidance or reference to interpret and apply international law.

They help clarify legal rules, settle disputes between states, and develop international legal principles over time. Judicial decisions are considered a subsidiary source of international law under Article 38(1)(d) of the ICJ Statute.

Theories of International Law

F Natural Law Theory:

Natural Law Theory believes that international law is based on morality, ethics, and human reason, not just on what countries agree to. According to this theory, certain laws are universal and apply to all human beings, whether or not they are written in treaties or customs.

One of the most famous supporters of this theory is Hugo Grotius, known as the "Father of International Law." He argued that even in war, states must follow moral rules because they come from natural law.

 

F Positivist Theory:

The Positivist Theory of international law argues that law is created by states through their consent, and it becomes binding only if states agree to follow it. This school of thought rejects morality or natural justice as the basis of law. According to positivists, international law is valid not because it is morally right, but because it is accepted and practiced by sovereign states.

Famous jurist Lassa Oppenheim, a leading positivist, defined international law as a body of rules created by states, and binding on them only when they have expressly or implicitly agreed to those rules through treaties, customs, or international agreements. The positivist approach became popular in the 19th century, when the idea of state sovereignty and non-interference was strongly upheld.

 

Subject of International Law

 

F State:

States are the primary and most important subjects of international law. They have full international legal personality, meaning they have rights, duties, and the capacity to enter into legal relations with other states and international bodies.

According to the Montevideo Convention, a state must have:

Ø  A permanent population

Ø  A defined territory

Ø  A government

Ø  The capacity to enter into relations with other states.

 

F International Organizations:

International Organizations are created by states through treaties or agreements to achieve common goals. They are considered secondary subjects of international law because they have a limited legal personality, which means they have some rights and duties, but not as many as states.

Examples: United Nations (UN), World Health Organization (WHO), International Monetary Fund (IMF), World Trade Organization (WTO), European Union (EU), etc…

 

F Individuals:

In the modern era, individuals have gained recognition as limited subjects with certain rights and responsibilities under international law.

Example: The Nuremberg Trials were a series of military tribunals held after World War II, conducted by the Allied powers to prosecute high-ranking Nazi officials for crimes committed during the war.

 

F Non-Governmental Organizations (NGOs) in International Law:

Non-Governmental Organizations (NGOs) are independent, non-profit groups that work at local, national, or international levels to promote causes like human rights, environmental protection, health, and disaster relief. Although NGOs are not full subjects of international law like states or international organizations, they play an important and influential role in global legal processes indirectly.

 

F Multinational Corporations:

Multinational Corporations (MNCs) are large private companies that operate in multiple countries. Examples include Apple, Google, Shell, and Nestlé. Although MNCs are not full subjects of international law like states or international organizations, they have become increasingly important actors due to globalization.

 

F Peoples and Liberation movements:

Peoples and liberation movements are recognized as limited subjects of international law when fighting against colonialism, foreign occupation, or racial oppression. They are supported by the principle of self-determination, as stated in the UN Charter and other international declarations. These groups can gain observer status in international organizations and may act on behalf of their people.

Example: The Palestine Liberation Organization (PLO), recognized by the UN in 1974. Though not full subjects like states, they are important in the struggle for independence and human rights.

 

Conclusion

International law has developed from ancient customs to a modern legal system that governs the behaviour of states and global actors. It has evolved through different historical periods and now addresses diverse global issues like human rights, security, trade, and the environment. Supported by treaties, customs, and legal principles, and shaped by both natural and positivist theories, international law today includes not only states but also individuals, organizations, and other entities. Despite enforcement challenges, it plays a key role in maintaining global peace, justice, and cooperation.