International law is an umbrella term for various sets of legal rules which are recognized by states and organizations. These rules regulate the interaction between organizations and nations. They also regulate the treatment of individuals, as well as the conduct of hostilities and global communications.

The concept of international law originated in the ancient Middle East, where cooperative agreements were negotiated between the rulers of the region. In the 15th century, the introduction of the printing press led to the development of science, which further influenced the study of international law.

A variety of political and economic interests played a role in the development of international law. This included the concept of nation-states, which were established as independent sovereign entities by the Peace of Westphalia in 1648. However, as the concept of nation-states became more complex, it also became necessary to create more sophisticated rules.

The development of the modern legal system has primarily ceded power from individual states to international bodies. This has led to an expansion of the scope of international law. It now covers all human activities, including corporations and non-state groups.

Many scholars, such as John Stuart Mill, have advocated for a more universal application of international law. These efforts have been supported by developing world democracies.

While there is no universal governing body for international law, a variety of supranational judicial organs can help states understand and interpret the law. These include the International Court of Justice (ICJ) and the United Nations’ International Criminal Court.