“Above all, the Russian strongman is a student of Clausewitz.”
Not Clausewitz, but Machiavelli...
They might have deemed Machiavelli politically-incorrect in American schools, but it is still taught in many places.
The more malevolent side of Putin comes from a man named Aleksandr Dugin. A neo-Eurasian who detests the west and has, they say, had considerable influence on Putin.