History of the International System States engage with one
another in an environment known as the international system. All
states are considered to be sovereign, and some states are more
powerful than others. The system has a number of informal rules
about how things should be done, but these rules are not
binding. International relations have existed as long as states
themselves. But the modern international system under which we
live today is only a few centuries old. Significant events have
marked the milestones in the development of the international
system. The Peace of Westphalia (1648) In 1648, the Peace of
Westphalia, which ended the Thirty Years’ War between Catholic
states and Protestant states in western and central Europe,
established our modern international system. It declared that
the sovereign leader of each nation-state could do as she or he
wished within its borders and established the state as the main
actor in global politics. From that point forward, the
international system has consiste