He felt like the other nations had been completely unjust to Germany and therefore Germany needs to take revenge and once again rise. Once he finally gained enough momentum he was able to start World War II in order to restore German pride.
Hitler's Reichstag Speech in which his response to Roosevelt's demands of 1939 that he refrains from interfering in the the politics of neighbouring European countries and announces his decision to abolish the Anglo-German Naval Agreement of 1936.