The situation changed visibly when sentimental reasons and long-term political aims gave way to a stern, ruthless nationalist ideology which would brook no compromise. Hitler had categorically demanded the Anschluss in "Mein Kampf".... As early as 1923 Hitler had decide that, if necessary, the National-Socialists must take over the government in Austria by force.

p. 39 - The Brutal Takeover: The Austrian ex-Chancellor's account of the Anschluss of Austria by Hitler, 1971