There are few points in history that have been as decisive as World War I. The world before The Great War was unambiguously Euro-centric. Western Europe, in addition to having the wealthiest and most technologically advanced nations on earth, had cultivated vast colonies that spanned the globe.
Covering over 22% of the earth's land area and encompassing fully 20% of its population, the sun never set on the British Empire. The expansive French colonies stretched over vast swaths of Africa, Southeast Asia and numerous smaller territories. Germany had fledgling colonies in Africa and the South Pacific. Even the tiny countries of Belgium, Portugal and the Netherlands each held significant overseas possessions. The U.S., in comparison, was still considered a cultural, if not technological, backwater.
In many ways, the world before World War I was a direct outgrowth of medieval feudal European history. Kings, Emperors, Kaisers and Czars ruled these kingdoms just as their ancestors had done for centuries before them. In a world of distinct and largely rigid social classes, being a member of nobility had real meaning. In fact, only two nations in the entirety of Europe - both well ahead of their time - didn't have monarchs in the first decade of the 20th century: The Swiss Confederation and the Republic of France.
Technologically, the period immediately following 1914 was far more transformative than the centuries that preceded it. Before World War I people traveled by horse and carriage, train and, if traveling overseas, by boat. Cars were still rare - a plaything of the rich - and most people had never seen an airplane, much less ridden in one. Likewise, the telephone and wireless telegraph (radio) were still in their infancy before the Great War, available only to the rich. The roaring 1920s was really the decade when telecommunications really became available to the masses.
When World War I finally arrived it shattered the old world order irreparably. As the British Foreign Secretary Sir Edward Grey ominously commented at the time, "The lamps are going out all over Europe." As the war ground to its brutal conclusion the centuries old empires of Czarist Russia and Austro-Hungary collapsed with shocking suddenness. The defeated German Kaiser abdicated in humiliation, fleeing to exile in Holland. Republics sprang up like weeds in the aftermath of the war, particularly in Eastern Europe. Suddenly, monarchy didn't seem as necessary anymore, as if the natural political order of the universe had been overturned.
World War I marked the beginning of the end of European Exceptionalism, monarchism and colonialism. Sure, the British and French Empires, among others, lingered on into the 1920s and 1930s. But the inter-war period was a hazy dream-time of wistful denial on the part of Europeans; in reality their empires had been fatally wounded.
Imperial subjects from India to Vietnam to Algeria gradually became ever more aware of their national identities. Nationalism that had been sporadic and ill-organized before the Great War suddenly became an irresistible force, inevitably tearing these empires asunder. The great European empires could not - and did not - long survive these developments. The world after 1914 was never the same.
