The study of the ways states interact with each other and with non-state entities, such as international organizations and subnational communities. It is a major multidiscipline in the social sciences, with links to political science, anthropology, economics, geography, history, law, and philosophy. It uses various theoretical frameworks to analyse patterns of state behaviour and global phenomena. These include realism, liberalism and constructivism.
The belief that a state has sovereignty over its territory, as defined in the Six Books of the Commonwealth by Jean Bodin in 1576, and that the sovereign powers’ rights extend to all inhabitants of those territories, including other states, individuals, corporations, and non-governmental organisations. The idea is fundamental to international relations.
A state dissatisfied with the existing global order and that wants to revise it. Examples include Russia and China, which are often seen as revisionists.
The process by which states encourage and promote activities that benefit their common interests. Examples are trade agreements, military alliances and peacekeeping operations.
The practice of sending diplomatic messages between one state and another, usually in the form of written notes. Diplomacy is a vital part of international relations and helps to resolve disputes. It also enables countries to share information about their activities with other states and the wider world. A major objective of the field is to reduce reliance on war and violence. It has been used to tackle major issues such as climate change, terrorism and pandemics, which transcend national borders and require collective action by nations.