Westphalian System

The Westphalian System is the conventional shorthand for the model of international relations in which the sovereign state is the principal actor, each state exercises exclusive jurisdiction over its territory and population, and states formally recognize one another as juridical equals. It is named after the Peace of Westphalia (1648), the pair of treaties signed at Münster and Osnabrück that ended the Thirty Years' War in the Holy Roman Empire and the Eighty Years' War between Spain and the Dutch Republic.

Scholars typically associate the system with four interlocking norms:

• Territorial sovereignty – authority is bounded by fixed borders.
• Legal equality of states – formally, a microstate and a great power have the same standing in international law.
• Non-intervention – states do not interfere in the internal affairs of others, a principle later codified in Article 2(4) and Article 2(7) of the UN Charter.
• Recognition – statehood is constituted partly through mutual acknowledgment by peers.

Historians such as Andreas Osiander have argued that 1648 itself did not invent these principles and that the "Westphalian myth" was largely constructed by 19th- and 20th-century theorists. Even so, the label is universally used in diplomatic and academic discourse to describe the state-centric order that has structured global politics for the modern era.

The system is frequently described as eroding under pressures from supranational bodies (the EU), international criminal jurisdiction (the ICC), humanitarian intervention doctrines such as the Responsibility to Protect (2005 World Summit Outcome Document), transnational corporations, and cyber and climate threats that ignore borders. Despite these challenges, sovereign equality and non-interference remain the default grammar of the UN General Assembly and most bilateral diplomacy.