Introduction to World War I (1914–1919)

World War I, often referred to as “the Great War,” was without precedent as nations around the world simultaneously took up arms against each other. The war’s effects were vast and profound, with consequences that reverberated throughout the twentieth century. Human casualties were enormous. It is estimated that over ten million soldiers died and twenty million were wounded as a direct result of the war. The use of chemical weapons, bombardments from the air, and the century’s first genocide account for the dramatic loss of military personnel. Civilians died in equally shocking numbers due to worldwide hunger and influenza epidemics. As a result of these vast casualties, Russia lost two million people and Serbia lost fully one-third of its population. The staggering loss of human life was just one aspect of the war that changed the world forever.

The assassination on June 28, 1914, of Austro-Hungarian Archduke Franz Ferdinand marks the beginning of World War I, but the underlying causes are debated. Historians provide a number of explanations, including the desire for greater wealth and territory, a massive arms race, a series of treaties that ensured that all of Europe would be dragged into a war begun by one nation, social turmoil brought on by the Industrial Revolution, and the simple miscalculation of ruling generals.

A complicated system of European alliances accounts for one of the leading causes of the war. A growing tide of nationalism, especially strong in the Balkan territories under Austro-Hungarian rule, also contributed to rising tensions. Nationalism had been a rising trend in Europe for several decades before the war, which causes some historians to wonder why the eruption of World War I did not happen sooner. Finally, the last leading cause of World War I was an unprecedented and aggressive pursuit of colonial holdings. Europe, Japan, and the United States were the primary competitors in this “empire for empire’s sake” rivalry of the late nineteenth and early twentieth centuries.

World War I caused global change on three levels: political, cultural, and socioeconomic. After Germany surrendered and the war ended, reconstruction efforts were made. One of the results of those efforts was the Treaty of Versailles, the most significant and well-known of the postwar treaties. In it, Germany was forced to acknowledge responsibility for causing the war, among other things, and the League of Nations, decades in the making, was created. The map of the world was redrawn as a result of World War I and the many treaties that grew out of it. New nation-states emerged when boundary lines were redrawn, causing political and cultural struggles that linger to this day. The Russian Revolution and the appearance of waves of eastern and southern European immigrants on American shores immediately following the war led to a rise in Americans’ fear of Communism. International anxiety, increased mechanization, and the spread of industrialization brought a fundamental shift in the way people perceived their places in the changing modern world.