EVOLUTION OF MODERN STATE SYSTEM

2.6. The World Wars and the Reshaping of the International System

World War I marked a profound crisis for the European-centered state system. The collapse of the Austro-Hungarian, Ottoman, Russian, and German empires led to the creation of new nation-states in Central and Eastern Europe, based on the principle of national self-determination, championed by U.S. President Woodrow Wilson. The establishment of the League of Nations was a significant innovation, aiming to provide a collective security mechanism and prevent future wars. However, the League lacked enforcement power and failed to prevent aggression in the 1930s.

World War II (1939–1945) further transformed the international system. The devastation of the war and the Holocaust discredited imperialism and totalitarianism, leading to the decolonization movement after 1945. Dozens of new states emerged in Asia, Africa, and the Middle East, joining the international community.

The United Nations (UN) replaced the League of Nations in 1945, embodying the principles of sovereign equality and collective security. Unlike its predecessor, the UN had stronger institutional mechanisms, including the Security Council, to maintain peace.