A broad field of study that examines the interactions among nations, encompassing such subfields as international law and politics, economics, history, geography and philosophy. It is a major multidiscipline in the social sciences, with prominent schools of thought ranging from realism to liberalism.
The practice and profession of managing international relations, typically by representatives abroad (see ambassador). As the United States has interests in more than 190 countries, its diplomats and other personnel involved in foreign policy must deal with a wide range of issues.
In a country, supreme power over the territory it governs. This idea is the basis of the modern international system outlined by the Treaty of Westphalia in 1648 and embodied in the notion that nations–monarchs then, governments now–control what happens within their borders. See also sphere of influence, Responsibility to protect, Hegemon, Balance of power.
A group of nations or regions that share a common language, culture or religion. Historically, this has largely been a geographic term, but it is also used as an idea to describe a political bloc, such as the NATO-Warsaw Pact grouping of Central Europe or the BRICS intergovernmental organization that aims to promote economic co-operation in Africa.
The five largest emerging economies–Brazil, Russia, India, China and South Africa–plus Nigeria are a loosely-defined regional bloc that was formed in 1975. The group is dominated by Nigeria and has been moderately successful in promoting economic cooperation in the region and sending peacekeeping troops to other African countries beset by civil war.