The book is literally called "Unhumans: The Secret History of Communist Revolutions (and How to Crush Them)".
Vance is like a presidential campaign's worst nightmare from a vetting perspective.
The authors are Jack Posobiec and Joshua Lisec. Posobiec is an alt-right conspiracy theorist who spread the great replacement theory and Pizzagate.
Steve Bannon did the foreword to the book and Vance provided a blurb for the book.