The history of international relations is often traced back to the Peace of Westphalia of 1648, where the modern state system was developed. Prior to this, the European medieval organization of political authority was based on a vaguely hierarchical religious order.
A part from political science, IR draws upon such diverse fields as economics, history, international low, philosophy, geography, social work, sociology, psychology and cultural studies/culturology. It involves a diverse range of issues including but not limited to: globalization, state sovereignty, ecological sustainability, nuclear proliferation, nationalism, economic development, global finance, terrorism, organized crime, human security, foreign interventionism and human rights.