I am looking for specific political decisions made by him that lead to the tensions in early 20th century and world war 1? I know that he was building up the army and was very aggressive, which made other big European powers to build up their own armies and smaller countries to seek alliances with them.

If you guys could point me to some sources that describe my question, or just anything that explains how Kaiser Wilhelm II was responsible for ww1 and tensions leading up to it.