Hitler did that on his own.
Anyone who had bothered to skim through "Mein Kampf" would know where Hitler derived his ideas.
To believe that Hitler acted alone is a problem. It is not hard to find the evidence linking Islam, Nazism and the liberal left-a union that OFFICIALLY began pre-WWII. Mahoney's book provides the evidence-but it's rather easy to find on your own if you are willing to accept the truth.