International Law: Definition, Nature and Basis

About this topic

Ships entering foreign ports, aircraft crossing the skies of other countries and parcels moving between nations all follow rules that no single country made. Those rules are international law. Yet some of history's most respected legal minds insisted that it is not law at all.

The topic is best studied through four questions, each beginning with W:

1. What is international law? (definition)
2. Whether it is really law? (nature)
3. What is its weight, that is, how strong is it?
4. Why does it bind states at all? (basis)

Three problems to keep in mind

Each problem can be solved once the four questions are settled.

1. A country signs a treaty. A few years later, a new government comes to power and says that the treaty was the old government's promise, not its own. Is the country now free of the treaty?
2. The World Court decides a case against a powerful country, and that country simply refuses to obey. Does that prove international law is not law?
3. India has never joined the Refugee Convention of 1951. Is India bound by that treaty anyway?

What is international law? (Definition)

Origin of the name

• For centuries, this branch of law was called the law of nations.
• Jeremy Bentham coined the word international, and with it the name international law, in his book An Introduction to the Principles of Morals and Legislation (printed in 1780, published in 1789).
• He used the term to separate the law between states from internal law, that is, the law inside a single state.

Oppenheim's classical definition

The classical definition comes from Professor Lassa Oppenheim's treatise, first published in 1905. He described the law of nations, or international law, as:

"the name for the body of customary and conventional rules which are considered legally binding by civilised States in their intercourse with each other."

The definition rests on two kinds of rules:

• Customary rules grow from the settled practice of states, followed out of a sense of legal duty.
• Conventional rules are those written in treaties.

Criticism of Oppenheim's definition

The definition suffers from two problems:

1. The word "civilised" belonged to the colonial age and kept many nations outside the hall.
2. Only states are included. No one except states gets a seat. Later developments showed that international organisations and individuals also have a place in international law.

Modern definition: Jennings and Watts

Because states were no longer the only participants, the definition had to grow. In the ninth edition of Oppenheim's International Law (1992), Sir Robert Jennings and Sir Arthur Watts defined international law as:

"the body of rules which are legally binding on States in their intercourse with each other. These rules are primarily those which govern the relations of States, but States are not the only subjects of international law. International organisations and, to some extent, also individuals may be subjects of rights conferred and duties imposed by international law."

Two changes stand out: the word "civilised" is dropped, and international organisations and, to some extent, individuals are recognised as subjects of international law.

Schwarzenberger's definition

Georg Schwarzenberger turned the guest list into an open invitation. For him, international law is:

"the body of legal rules which apply between sovereign States and such other entities as have been granted international personality."

• International personality is the capacity to carry rights and duties under international law, and to claim them.
• Whoever receives international personality is automatically inside the scope of international law.

Comparison of the definitions

Is international law really law? (Nature)

This is the sharpest debate in the subject. It is best studied like a courtroom: each objection, followed by its reply.

Objection 1: Law needs a commander

• Thomas Hobbes: law is what a sovereign commands. States have no common master, so the law of nations was simply the law of nature, binding only on conscience.
• John Austin (1832) sharpened the point. A law is a command from a political superior, and disobedience brings a sanction, that is, some evil or penalty. Since there is no political superior above states, rules between states are not law properly so called. They are "positive international morality", supported only by general opinion.

Reply: the evidence of history (Sir Henry Maine)

Sir Henry Maine pointed to Maharaja Ranjit Singh of Punjab, a ruler with absolute power who, Maine observed, never issued a command that Austin could call a law. The lives of his subjects were governed by their immemorial customs. If custom was law under an all-powerful ruler, it can be law between states too.

Objection 2: Law needs machinery

A complete legal system has four things:

1. someone to make law;
2. someone to enforce it;
3. a court to apply it; and
4. a penalty for breaking it.

Critics said the world had none of these in a dependable form. Thomas Erskine Holland therefore called international law "the vanishing point of jurisprudence".

Reply: Pollock's simpler test

Sir Frederick Pollock wrote:

"The only essential conditions for the existence of law and legal institutions are the existence of a political community and the recognition by its members of settled rules binding upon them in that capacity."

Applying the test to the world:

• States form a community; and
• they accept settled rules as binding on them.

Machinery makes a legal system stronger, but it is not what makes a rule a law.

Objection 3: States break international law whenever they please

Reply

• Breach does not destroy law. Someone jumps a red light every day, and nobody concludes that traffic law has stopped being law.
• When states break international law, they rarely deny that it exists. They argue instead that their conduct is permitted by it.
• The Indian Constitution itself recognises international law. Article 51(c), a Directive Principle, asks the State to endeavour to "foster respect for international law and treaty obligations in the dealings of organised peoples with one another".

Objections and replies at a glance

Conclusion of the debate

The answer depends on the definition of law one starts with.

• Measured with Austin's narrow ruler, international law falls short.
• Measured with Pollock's wider ruler, it passes, and that is the accepted view today.

Weight of international law: how strong is it?

International law has a strong voice but weak hands. It states duties clearly, but struggles to enforce them. Three weak spots explain this.

Weak spot 1: Enforcement

• The International Court of Justice (ICJ), the World Court, is the principal judicial organ of the United Nations.
• It has judges, but no officers or prison of its own.

Article 94 of the UN Charter provides:

"Each Member of the United Nations undertakes to comply with the decision of the International Court of Justice in any case to which it is a party."

It then adds:

"If any party to a case fails to perform the obligations incumbent upon it under a judgment rendered by the Court, the other party may have recourse to the Security Council, which may, if it deems necessary, make recommendations or decide upon measures to be taken to give effect to the judgment."

The difficulty is that the Security Council works under the veto of its five permanent members, so enforcement can be blocked.

Weak spot 2: Consent

• A treaty binds only the states that accept it.
• India has not joined the Refugee Convention of 1951, nor the Rome Statute of the International Criminal Court.
• Even when a state joins a treaty, it may attach a reservation.

Weak spot 3: Youth

• National legal systems have grown over centuries, but organised international institutions are recent.
• The League of Nations began in 1920, and the United Nations in 1945.

The hands are growing stronger

• Law-making treaties now do much of a legislature's work.
• The International Law Commission works on codifying the law.
• Under Chapter VII of the UN Charter, the Security Council can order enforcement measures.

Basis of international law: why does it bind states?

If no one stands above states, why are they bound at all? Ask a person why they kept a promise, and five answers may be heard. International lawyers have given the same five answers, and a sixth, middle school stands between them.

1. Pacta sunt servanda: "a promise is a promise"

• Pacta sunt servanda means agreements must be kept.
• The Italian jurist Dionisio Anzilotti saw it as the foundation stone from which the binding force of international law flows.
• Today, Article 26 of the Vienna Convention on the Law of Treaties, 1969, states: "Every treaty in force is binding upon the parties to it and must be performed by them in good faith."

2. Consent theory: "because I agreed"

• This is the theory of the positivists: states are bound because they have consented.
• Consent may be:
  • Express: written into a treaty; or
  • Tacit: shown silently when a state goes along with a custom year after year.
• Weakness: when a new state is born, it never agreed to the customary rules already in place, yet it is bound by them from its first day.

3. Auto-limitation theory: "because I chose to restrict myself"

• Georg Jellinek called this auto-limitation, or self-limitation.
• Nothing stands above the will of the state, but that will can bind itself.
• Criticism: a lock the prisoner can open is hardly a lock.

4. Naturalist school: "because it is right"

• Treats international law as part of the law of nature.
• Its rules are discovered through reason and justice.
• They are binding whether or not a state has agreed.

5. Fundamental rights theory: "because I have rights that need protection"

• This theory also grows from natural law.
• Natural law writers believed every human being is born with certain rights. Applying the same idea to states, each state holds basic rights of:
  • self-preservation;
  • independence;
  • equality; and
  • respect.
• International law exists to secure these rights.

6. Eclectic or Grotian school: the middle path

• Stands between the natural law camp and the camp of law created by the will of states.
• Named after Hugo Grotius, the Dutch scholar remembered as the father of international law, whose book on the law of war and peace came out in 1625.
• Grotius accepted both natural law and law created by the will of states; the eclectics followed that middle path.

Theories of basis at a glance

The three problems solved

1. New government, old treaty: the country is still bound. A treaty is made by the state, not by a passing government, and Article 26 of the Vienna Convention on the Law of Treaties demands performance in good faith.
2. Powerful country ignores the World Court: the country has broken the law, but a broken law is still law. This shows weak hands, not a missing voice.
3. India and the Refugee Convention of 1951: India is not bound by the Convention as a treaty, because treaties need consent. However, every state remains bound by general customary law.

Quick revision

• What it is: Bentham coined "international law"; Oppenheim (1905) limited it to civilised States; Jennings and Watts (1992) added international organisations and, to some extent, individuals; Schwarzenberger includes every entity with international personality.
• Whether it is law: Austin says "positive international morality"; Holland says "the vanishing point of jurisprudence"; Maine and Pollock reply that it is law, which is the accepted view today.
• Its weight: a strong voice but weak hands, with three weak spots: enforcement, consent and youth.
• Why it binds: pacta sunt servanda, consent, auto-limitation, naturalist, fundamental rights, and the eclectic or Grotian middle path.