World War I, which lasted from 1914 to 1918, was the first global conflict in human history. It involved the major powers of the world, including Germany, Austria-Hungary, and the Ottoman Empire on one side, and the United Kingdom, France, and Russia on the other. The United States joined the war in 1917, tipping the balance in favor of the Allies. The war ended with the Treaty of Versailles, which imposed harsh penalties on Germany and paved the way for World War II.
The causes of World War I are complex and multifaceted. One of the main factors was the system of alliances that had developed among the major powers of Europe. These alliances, which were designed to provide security and deter aggression, actually had the opposite effect. When one member of an alliance was attacked, its partners were obligated to come to its aid, leading to a cascade of declarations of war. Another factor was the arms race that had developed among the major powers.
The development of new technologies, such as machine guns and tanks, had made warfare more deadly and destructive than ever before. This led to a sense of unease and insecurity among the major powers, each of which felt the need to build up its military in order to deter its rivals. The war itself was characterized by a series of brutal battles that took place on multiple fronts. The Western Front, DW News Today which stretched from Belgium to Switzerland, was the site of some of the bloodiest fighting in the war.