International law is the set of rules, norms and standards generally recognized as binding between states. It establishes normative guidelines, methods, mechanisms and a common conceptual language for international actors – primarily sovereign states but increasingly also international organizations and some individuals.
The origins of international law can be traced back to ancient peace treaties and agreements between polities across the world. Among the earliest extant examples are the Mesopotamian city-states of Lagash and Umma (approximately 2100 BCE) and the Egyptian pharaoh Ramses II and the Hittite king Hattusilis III (1258 BCE).
The development of public international law has undergone rapid changes since the end of World War Two. These developments include the creation of a legal system governing the use of force, a system of collective security and the protection of human rights.
In recent years, international law has become much more diverse and broader, incorporating issues such as human rights, international humanitarian law, space law, and international trade. As a result, it has been influenced significantly by ethical principles and concerns.
Although many of the concepts and practices in international law are self-enforcing, compliance by individual states with the laws of other countries is not always easy to achieve. Because of state sovereignty, some countries might only halfheartedly participate in international treaties and agreements and fail to adhere to the terms that they agree to.
Consequently, international lawyers and political leaders have debated whether international law can be enforced effectively in the modern environment of state sovereignty. They argue that, in some cases, enforcement may be difficult and even impossible. This is especially the case when state governments deviate from the expected standards of conduct embodied in international laws, such as those that prohibit the use of violence or the destruction of property.