Europe reached its breaking point on June 28, 1914, Archduke Francis Ferdinand, heir to the Austria-Hungarian throne, was assassinated in Sarajevo by a Serbian nationalist belonging to an organization known as the Black Hand. Immediately following the assassination Germany pledged its full support to Austria-Hungary, pressuring them to declare war on Serbia, while France strengthened its backing of Russia. Convinced that the Serbian government had conspired against them, Austria-Hungary gave Serbia an unacceptable ultimatum. Unsatisfied, Austria-Hungary declared war on Serbia on July 28, 1914. The Germans threatened war on July 31 towards the Russians. On August 1, Germany declared war on Russia, and two days later, on France. The German invasion of Belgium to attack France, which violated Belgium's official neutrality, prompted Britain to declare war on Germany. World War I had begun.
In 1918, Woodrow Wilson laid out his 14 points proposal for ending the war. In it he established the base of a peace treaty and the base of the League of Nations. In it he said, "It is that the world be made fit and safe to live in; and particularly that it be made safe for every peace loving nation which, like our own, wishes to live its own life, determine its own institutuions, be assured of justice and fair dealing by the other peoples of the world as against selfish aggression." Wilson wanted the restoration of many parts of the world including: Belgium, France, Rumania, Serbia, and Montenegro. He felt very adamantly about this because he said, " unless justice be done to others, it will not be done to us." .
The Versailles Treaty was presented to Germany by the allied powers in 1919. The good things about this treaty is that it kept Germany together, the European map was basically re-drawn, and the league of nations is formed. This treaty basically stripped Germany of everything though.