International law is a set of rules and standards that govern a wide variety of issues, including international relations, war, diplomacy, human rights and the environment. In addition to its primary function of establishing normative guidelines and a common conceptual framework for states, international law has also been used as a basis for settling disputes between nations.

The development of international law is a complex process that draws on several sources, such as treaties, customs and general principles of law. Early legal scholars such as Alberico Gentili and Cornelius van Bynkershoek asserted that customs and treaties commonly consented to by various states were the foundation of international law.

Another source is general principles of law, which are generally recognized in systems of national law. In some areas of international law, such as criminal law, these rules may be more important than international law itself.

A major source of international law is the United Nations Charter, which prohibits the use of force and other forms of coercion against other states. Some international disputes are settled by negotiation, while others are referred to an international tribunal or court.

In 1948, the United Nations established the International Law Commission to promote the progressive development of international law. As an expert legal body, the Commission prepares draft conventions on subjects that have not been regulated by international law and codifies rules of international law in fields where there is extensive state practice. It often consults with the International Committee of the Red Cross, the International Court of Justice and UN specialized agencies depending on the subject.