World War II, also called Second World War, was a conflict that involved virtually every part of the world during the years 1939–45. The principal belligerents were the Axis powers—Germany, Italy, and Japan—and the Allies—France, Great Britain, the United States, the Soviet Union, and, to a lesser extent, China. It was the biggest conflict in history that had lasted almost six years. Nearly some 100 million people had been militarised, and 50 million had been killed (around 3% of the world's population).

All wars have significant social and economic impacts but this is especially so in the case of the First and Second World Wars. Their impact was very different to previous European conflicts that Britain had been involved in because of their scale, the involvement of the civilian population, and the extended powers and actions of the state. Because the state operated at a British level, many of the war’s impacts did not differ between England and Wales. However, the war did heightened Welsh national consciousness, despite the power of popular and political Britishness. Yet this was actually an existing long-term process and many of the impacts of the war were a quickening of trends already taking place.

The German Instrument of Surrender ended World War II in Europe on the night of May 8, 1945. The terms of Germany’s unconditional surrender had been discussed since January 1944 and further clarified at the Yalta conference. They established, among other things, that the Allied Representatives “will take such steps, including the complete disarmament, demilitarisation and dismemberment of Germany as they deem requisite for future peace and security.” The surrender of Japan was announced by Imperial Japan on August 15 and formally signed on September 2, 1945, bringing the hostilities of World War II to a close. Their terms of surrender included disarmament and occupation by Allied forces. The terms of Italy’s defeat were determined during the Paris Peace Conference in 1947, and included limits on their military and a ban on all fascist organizations. The unconditional surrender of Germany on May 8, 1945, and Japan on September 2, 1945, brought World War II to an end. Various documents and treaties placed stringent terms on Axis powers to prevent future hostilities.

Some 75 million people died in World War II, including about 20 million military personnel and 40 million civilians, many of whom died because of deliberate genocide, massacres, mass-bombings, disease, and starvation.

The major causes of World War II were numerous. They include the impact of the Treaty of Versailles following WWI, the worldwide economic depression, failure of appeasement, the rise of militarism in Germany and Japan, and the failure of the League of Nations.

Treaty of Versailles

Following World War I, the victorious Allied Powers met to decide Germany’s future. Germany was forced to sign the Treaty of Versailles.

Under this treaty, Germany had to accept guilt for the war and to pay reparations. Germany lost territory and was prohibited from having a large military.

The humiliation faced by Germany under this treaty, paved the way for the spread of Ultra-Nationalism in Germany.