After the devastation of World War I, the victorious western powers imposed a series of harsh treaties upon the defeated nations. These treaties stripped the Central Powers (Germany and Austria-Hungary, joined by Ottoman Turkey and Bulgaria) of substantial territories and imposed significant reparation payments.
Seldom before had the face of Europe been so fundamentally altered. As a direct result of war, the German, Austro-Hungarian, Russian, and Ottoman Empires ceased to exist. The Treaty of Saint-Germain-en-Laye of September 10, 1919, established the Republic of Austria, consisting of most of the truncated German-speaking regions of the Habsburg state. The Austrian Empire ceded crown lands to newly established successor states like Czechoslovakia, Poland, and the Kingdom of Slovenes, Croats, and Serbs, renamed Yugoslavia in 1929. It also relinquished the South Tyrol, Trieste, Trentino, and Istria to Italy, and Bukovina to Romania. An important tenet of the treaty barred Austria from compromising its newly formed independence. This restriction effectively barred it from unification with Germany, a goal long desired by "Pan-Germanists" and an active aim of Austrian-born Adolf Hitler and his National Socialist (Nazi) Party.
The other portion of the Dual Monarchy, Hungary also became an independent state: under the terms of the Treaty of Trianon (November 1920) Hungary ceded Transylvania to Romania; Slovakia and Transcarpathian Rus to the newly formed Czechoslovakia; and other Hungarian crown lands to the future Yugoslavia. The Ottoman Empire signed the Treaty of Sèvres on August 10, 1920, ending hostilities with the Allied Powers; but shortly thereafter a Turkish War of Independence began. The new Republic of Turkey, established in its aftermath, signed a superseding Treaty of Lausanne in 1923, effectively partitioning the old Ottoman Empire.
In January 1918, some ten months before the end of World War I, US President Woodrow Wilson had written a list of proposed war aims which he called the "Fourteen Points." Eight of these points dealt specifically with territorial and political settlements associated with the victory of the Entente Powers, including the idea of national self-determination for ethnic populations in Europe. The remainder of the principles focused on preventing war in the future, the last proposing a League of Nations to arbitrate further international disputes. Wilson hoped his proposal would bring about a just and lasting peace, a "peace without victory" to end the "war to end all wars."
When German leaders signed the armistice, many of them believed that the Fourteen Points would form the basis of the future peace treaty, but when the heads of the governments of the United States, Great Britain, France, and Italy met in Paris to discuss treaty terms, the European contingent of the "Big Four" had another plan altogether. Viewing Germany as the chief instigator of the conflict, the European Allied Powers ultimately imposed particularly stringent treaty obligations upon the defeated Germany.
The Treaty of Versailles, presented for German leaders to sign on May 7, 1919, forced Germany to concede territories to Belgium (Eupen-Malmédy), Czechoslovakia (Hultschin district), and Poland (Poznan, West Prussia, and Upper Silesia). Alsace and Lorraine, annexed in 1871 after the Franco-Prussian War, returned to France. All German overseas colonies became League of Nation Mandates, and the city of Danzig, with its large ethnically German population, became a Free City. The treaty demanded demilitarization and occupation of the Rhineland, and special status for the Saarland under French control; plebiscites were to determine the future of areas in northern Schleswig on the Danish-German frontier and parts of Upper Silesia.
Perhaps the most humiliating portion of the treaty for the defeated Germany was Article 231, commonly known as the "War Guilt Clause," which forced Germany to accept complete responsibility for initiating World War I. As such Germany was liable for all material damages, and France's premier Georges Clemenceau particularly insisted on imposing enormous reparation payments. Aware that Germany would probably not be able to pay such a towering debt, Clemenceau and the French nevertheless greatly feared rapid German recovery and a new war against France. Hence, the French sought in the postwar treaty system to limit Germany's efforts to regain its economic superiority and to rearm.
The German army was to be limited to 100,000 men, and conscription proscribed. The treaty restricted the Navy to vessels under 100,000 tons, with a ban on the acquisition or maintenance of a submarine fleet. Moreover, Germany was forbidden to maintain an air force. Germany was required to conduct war crimes proceedings against the Kaiser and other leaders for waging aggressive war; the Leipzig Trial, without the Kaiser or other significant national leaders in the dock, resulted mainly in acquittals and was widely perceived as a sham, even in Germany.
The newly formed German democratic government saw the Versailles Treaty as a "dictated peace" (Diktat). Although France, which had suffered more materially than the other parties in the "Big Four," had insisted upon harsh terms, the peace treaty did not ultimately help to settle the international disputes which had initiated World War I. On the contrary, it tended to hinder inter-European cooperation and make more fractious the underlying issues which had caused the war in the first place. The dreadful sacrifices of war and tremendous loss of life, suffered on all sides, weighed heavily not only upon the losers of the conflict, but also upon those combatants on the winning side, like Italy, whose postwar spoils seemed incommensurate with the terrible price its nation had paid in blood and material goods.
For the populations of the defeated powers—Germany, Austria, Hungary, and Bulgaria—the respective peace treaties appeared an unfair punishment. Their governments, whether democratic as in Germany or Austria, or authoritarian, in the case of Hungary and, intermittently, in Bulgaria, quickly resorted to violating the military and financial terms of the accords. Efforts to revise and defy the more burdensome provisions of the peace became a key element in their respective foreign policies and proved a destabilizing element in international politics. For example, the war guilt clause, its incumbent reparation payments, and the limitations on the German military were particularly onerous in the minds of most Germans. Revision of the Versailles Treaty represented one of the platforms that gave radical right wing parties in Germany, including Hitler's Nazi Party, such credibility to mainstream voters in the early 1920s and early 1930s.
Promises to rearm, to reclaim German territory, particularly in the East, to remilitarize the Rhineland, and regain prominence again among the European and world powers after such a humiliating defeat and peace, stoked ultranationalist sentiment and helped average voters to often overlook the more radical tenets of Nazi ideology.