International Law

International law definition

International law is a growing and evolving body of rules, norms, and conventions that define what is acceptable behaviour between sovereign states. It aims to standardise, organise international relations to attain humanity's most important goals. It, therefore, applies to themes such as war, diplomacy, trade, environmental protection and human rights.

It generally applies to nations rather than individuals, but it can also apply to international organisations such as the European Union.

International law is not binding but is based on the concept of “agreement must be kept”, from the Latin pacta sunt servanda. Countries typically abide by it through consent in the knowledge that doing so is mutually beneficial, and not doing so, may lead to economic, diplomatic, or military consequences.

International law is based on international treaties, individual countries' general practice that translates into international customs, and general legal principles.

History of international law

The history of international law goes as far back as the history of the written word. Also, as societies are constantly changing, so are the norms that regulate international behaviour.

Let's have a closer look.

Ancient International Law

Early forms of international law were created as soon as different, independent states emerged within regions of the world. A good example of ancient international law is the Egyptian and the Hittite peace treaty.

We have examples of rules regarding war, the treatment of neutral parties, the observation of borders, the treatment of foreigners and international conduct from Ancient Greece (from 1200 BCE), the Roman Empire (from 625 BCE), China (from 1570 BCE), and the ancient Indian Subcontinent (from 1500 BCE).

In terms of the origin of international humanitarian law, we look at the ancient Islamic world. In the 7th Century C.E. the Caliphate institutionalised behaviours necessary to limit military damage and the treatment of prisoners of war.

During the Middle Ages, (500-1500 C.E.) the principles of natural law were bound with religious principles and applied to relations between states. International law was mainly concerned with defining “just war”.

Modern international law

Several historical events catalysed the modern development of international law.

• The development of the printing press (1440).

• The arrival of Greek thinkers to Europe following the fall of the Byzantine Empire (1453).

• The emergence of the concepts of natural rights such as life and liberty in the Enlightenment (from the 17th century)

• The consolidation of European states.

The Dutch lawyer Hugo Grotius (1583-1645) is considered one of the fathers of international law. He understood international relations to be governed by laws, customs and mutual agreements rather than force and warfare.

Grotius secularised International law in his work On the Law of War and Peace¹ and articulated the principles of natural law that all countries could agree on independently of local customs and differences.

He also inspired the two schools of thought on international law: the naturalists, who prioritise natural law, and the positivists, who prioritise positive law.

Fig. 3 Portrait of Hugo Grotius

The Westphalian system

The Peace of Westphalia was a key historical event in the modern development of international law.

It lead to what was retrospectively named the Westphalian system. It was a system that recognised equality between, and national sovereignty of existing nation-states. The Westphalian system also cemented the principle of inviolability of a nation's borders and secured acceptance and tolerance for religious choices.

Following the Peace of Westphalia, nations became richer and more complex and started developing codified legal systems where naturalists and positivist principles were merged and synthesised.

European colonisation (starting in the 16th century) spread the concept of sovereignty to many parts of the world.

20th Century Developments in International Law

The creation of the United Nations (1945) following the 2 world wars exemplified a further attempt to further the principles of international law.

International law became even more “international” when, following the process of decolonisation (started in the 1960s), many newly independent states could take part in, and influence international law.

The recent process of globalisation means social, cultural, economic, political and diplomatic interactions between states are part of everyday life.

Since the United Nations was formed, many other organisations such as the World Health Organisation have emerged to regulate, support and moderate international interactions.

Types of international law

The body of International law can be subdivided into public and private international law and supranational law.

Public international law

Public international law coincides with the current definition of International law. It's the body of norms that standardises and regulates behaviour between countries.

Private International law

Private international law, also called “conflict of laws” refers to the discrepancies between international law and countries' own laws, also called municipal law. It regulates which body of law has jurisdiction when an internal case has an international or foreign element.

Supranational law

Supranational law covers the legislation of a regional or international body that individual countries sign up for. By doing so, the countries explicitly give up their right to make judicial decisions.

International law human rights

International human rights law is the body of law intended to promote and ensure the observance of human rights everywhere.

International human rights law is mainly constituted by treaties and international customs.

The Universal Declaration of Human Rights (1948) is a United Nations declaration that enshrines human rights. It is not binding, but it is used as a base for international human rights instruments.

To protect and promote human rights in specific regions of the world, international human rights law is supplemented by regional systems.

The enforcement of human rights law is the responsibility of individual states, as there is no international human rights court. There are, however, regional courts such as the European Court of Human rights and the Inter-American Court of Human Rights which enforce human rights law in their respective regions. Also, the International Criminal Court hasn't got specific jurisdiction over human rights but does cover matters of genocide and crimes against humanity.

International law examples

A good example of how the international community can work together to regulate behaviour and benefit al is International environmental law.

International cooperation between countries often means a level of sacrifice for individual countries. This makes International environmental law “worth” it when there is a collective benefit, and only necessary when the problem to solve crosses national boundaries, such as air or water pollution; or is caused by international actions, such as the international of elephant ivory.

Then, International environmental law takes the form of binding treaties or non-binding agreements. One of the main international organisations coordinating and promoting international environmental law is the UN. Presently there are no bodies that can enforce international environmental law, however regional courts and the International Court of Justice have a degree of jurisdiction on the matter.