Austria
The Treaty of Saint-Germain of 1919 (for Hungary the Treaty of Trianon of 1920) confirmed and consolidated the new order of Central Europe which to a great extent had been established in November 1918, creating new states and altering others. The German-speaking parts of Austria which had been part of Austria-Hungary were reduced to a rump state named The Republic of German-Austria (German: "Republik Deutschösterreich"). The desire for "Anschluss" (annexation of Austria to Germany) was a popular opinion shared by all social circles in both Austria and Germany. On 12 November, German-Austria was declared a republic, and named Social Democrat Karl Renner as provisional chancellor. On the same day it drafted a provisional constitution that stated that "German-Austria is a democratic republic" (Article 1) and "German-Austria is an integral part of the German reich" (Article 2). The Treaty of Saint Germain and the Treaty of Versailles explicitly forbid union between Austria and Germany. The treaties also forced German-Austria to rename itself as "Republic of Austria" which consequently led to the first Austrian Republic.
Austrian nationalism
German nationalism began to rise rapidly within the German Confederation, in 1866 the feud between the two most powerful German states Austria and Prussia finally came to a head in the German war in 1866. The Austrians favoured the Greater Germany unification but were not willing to give up any of the non-German-speaking land inside of the Austrian Empire and take second place to Prussia. The Prussians however wanted to unify Germany as Little Germany primarily by the Kingdom of Prussia, whilst excluding Austria. In the final battle of the German war ("Battle of Königgrätz") the Prussians successfully defeated the Austrians and succeeded in creating the North German Confederation. In 1871, Germany was unified as a nation-state as the German Empire that was Prussian-led and without Austria. Nevertheless, the integration of the Austrians remained a strong desire for many people of both Austria and Germany, especially among the liberals, the social democrats and also the Catholics who were a minority within the Protestant Germany.