Prescience in “The Civil War in France.”

Let me share with you an excerpt from the introduction to “The Civil War in France: Address of the General Council of the International Working Men’s Association.”, written 1891 by Frederick Engels.
‘ And has not the prediction been proved to the letter, that the annexation of Alsace-Lorraine would “force France into the arms of Russia,” and that after this annexation Germany must either become the avowed servant of Russia, or must, after some short respite, arm for a new war, and, moreover, “a race war against the combined Slavonic and Roman races”?” ‘
Written 2 years before Adolf Hitler was born, this flips my awareness right round. A puppet to forces beyond his ken. I had already known about the major bias in then-contemporary German history books, but the incredible comprehension of Mr. Engels staggers me.