International Law

Table of Contents

What is International Law?

International law, in general, sets out the rules that apply to the relationships between states. It also sets out rules on many issues that states have agreed are of international importance.

Origins of international law

International legal obligations come from a number of different sources, including treaties, international customary law, general principles of law and United Nations resolutions.

The development of a body of international law, which is central to promoting economic and social development, as well as to advancing international peace and security, is among the greatest achievements of the United Nations.

How nations treat international law

Individual states take different approaches to their international obligations. Some treat international law as part of their domestic law. Others (including the UK) see international law as separate to domestic law, and require domestic legislation to implement international obligations.

How many international laws are there?

Over the years more than 560 multilateral treaties have been deposited with the UN Secretary-General. Many other treaties are deposited with governments or other entities. The treaties cover a broad range of subject matters such as human rights, disarmament and protection of the environment.

Disputes and breaches of international law

The 1969 Vienna Convention on the Law of Treaties (VCLT) sets out the rules relating to the formation, termination, conclusion, interpretation, and validity of treaties. Most treaties provide their own consequences and dispute settlement procedures for a breach of the rules they set out.

There are many examples in international affairs of disputes going unresolved, or allegations of breaches of international law that are never formally adjudicated and decided upon.