Hitler's Quote

Basically, Austria is a German-speaking country that was part of the multi-ethnic Austro-Hungarian Empire. After WW1 it became a Republic, even though the majority of Austrians and Germans would have preferred a union with Germany.

The Treaty of Versailles disallowed this, which came as a surprise to most Austrians and Germans. Both nations were under the false impression that a basic tenant of the post-war peace would be the uniting of Europe's various ethnic groups into unifying states. This was a wonderful talking point for the politician, Adolf Hitler, who was born in Austria.Adolf Hitler, from Mein Kampf: "German Austria must be restored to the great German motherland; and not, indeed, on any grounds of economic calculation whatsoever. No, no. Even if the union were a matter of economic indifference, and even if it were to be disadvantageous from the economic standpoint, still it ought to take place. People of the same blood should be in the same Reich. The German people will have no right to engage in a colonial policy until they shall have brought all their children together in one state. When the territory of the Reich embraces all the Germans and finds itself unable to assure them a livelihood, only then can the moral right arise from the need of the people, to acquire foreign territory. The plough is then the sword; and the tears of war will produce the daily bread for the generations to come...To demand that the 1914 frontiers should be restored is a glaring political absurdity that is fraught with . such consequences as to make the claim itself appear criminal. The confines of the Reich as they existed in 1914 were thoroughly illogical because they were not really complete, in the sense of including all the members of the German nation. Nor were they reasonable, in view of the geographical exigencies of military defense. They were not the consequences of a political plan which had been well considered and carried out, but they were temporary frontiers established in virtue of a political struggle that had not been brought to a finish; and indeed, they were partly the chance result of circumstan ces."

Hitler made it his business to unite the two states, and did so in the Anschlus of 1938. After WW2, Austria and Germany were once again separated into two states.