Although Adolf Hitler was born in Austria (technically, in the Austrian-Hungarian Empire, practically right on the border between Austria and Germany), since his early teens at least he was a deep, sincere, committed and diehard patriot of Greater Germany.
Which in his opinion had to include all territories with predominantly German-speaking population. Including, obviously, Austria. Interestingly enough, Adolf Hitler never considered himself an Austrian – only German.
Millions of Germans and Austrians shared this conviction of his (i.e. about the necessity of integrating Austria into the Greater German Reich)… however, it was not necessarily such a good idea.
The first reason for it not being such a good idea was religious – Austria was overwhelmingly Roman Catholic while Germany was basically a Protestant (Lutheran) Prussia with some add-ons.
The second one was historical and cultural – for centuries Austria was a part of Austrian-Hungarian Empire which was not only culturally different from Prussia (the core of Germany), but also was mostly a rival (and frequently even an enemy) of the latter.
However, these considerations did not matter to Adolf Hitler. Who since his early teens was a firm proponent of the idea of “Ein Volk – Ein Reich”. And a diehard patriot of both. To which later he added “Ein Führer”.
Adolf Hitler was mostly an idealist and a mystic (which ultimately contributed heavily to his downfall). However, his deep, passionate, sincere and very powerful love for Germany and Germans (these two concepts are not the same) was in many cases very pragmatic. Especially after the signing of the Treaty of Versailles, which some historians (correctly) believed to be the worst blunder in human history.
By the time he joined then-still-DAP in September of 1919, Adolf Hitler already had a very clear idea of what he wanted to do for his beloved Greater Germany.
Unite all territories with predominantly German population into one German Reich (including Austria and territories taken away at gunpoint by the “Criminals of Versailles”). Remove all constraints imposed by that (very literally) crime of the century.
Radically improve the management systems in businesses, government entities and non-profit organizations. And, of course, of the whole financial, economic, government and social system.
Transform a defeated, economically and financially devastated, ransacked, depressed country into a global political, economic and military superpower – the most powerful nation on Earth. Make Germany self-sufficient in foodstuffs and basic raw materials to guarantee that the horrors of the Blockade of Germany and the Great Hunger of 1917-19 never happen again.
With the ultimate objective of making the German people the happiest nation on Earth – and in human history. And – last but not the least – the nation of genuine Übermenschen. Superhuman beings that utilize 100% of their productive and creative potential – not just 10% (at most) as the “regular Homo Sapiens”.
By the outbreak of the Second Great War (contrary to a popular misconception, started by Britain and France, albeit provoked by Germany – more precisely, by its invasion of Poland), Adolf Hitler pretty much achieved all the abovementioned objectives.
With the exception of self-sufficiency in foodstuffs and raw materials – that’s exactly he annexed the whole of Czechoslovakia invaded Poland. With the ultimate objective of invading, conquering and occupying the most lucrative parts of the latter’s giant neighbor – the Soviet Union.
Unfortunately for Adolf Hitler, Germany (and very possibly for the whole world), he failed miserably. He lost the Second Great War (unlike the First one, this was lost on both fronts), was forced to commit suicide and left Germany far, far worse off than it had been in August of 1939 – before his ultimately ill-fated invasion of Poland.
And committed probably the worst mass murders and other crime against humanity in human history in the process.