Below are two of the more famous books in history, threaded together, chapter by chapter. The first is The Prince by Niccolo Machiavelli and the second is Frederick the Great's response, Anti-Machiavel.
Both books have entered the realm of the classics - Machiavelli's work for its cynicism and Frederick the Great's for its idealism. Both are written by men with experience in the art of statecraft.
So neither can be dismissed out of hand as exercises in theory, of wishful hopes. The Prince may have marked the end of Machiavelli's career as diplomat, and Anti-Machiavel the beginning of Frederick the Great's as King of Prussia, but the commonality is that both works are the refining of experience in the often anarchic world of international politics.
Here are the links to each. Just remember that the chapter of one book is linked to the corresponding chapter in the other, so it matters little which one you start with. Each book is in a file of its own, which does make for slow loading when first you access it, but this will be made up for by the convenience of having each volume's internal table of contents access one file only. Slow now; faster later.
There's also a surprise in each book, for convenience's sake too. Welcome to the world of both:
...And Frederick The Great's answer to it.