The correct answer to this open question is the following.
The information from this document that might be useful if you wanted to explain that Germany had an aggressive foreign policy was the political and personal ideas that Hitler had about supremacy and racism since he was young.
We are talking about the document called "Mein Kampf," the autobiography of Nazi leader Adolph Hitler that could be translated as "My Struggle." Published in 1925, the information contained in the document explains why he hated the Jews so much and his intention to start persecution to capture them. He also refers to his foreign policy of conquering and domination of some parts of Europe and Russia.