Uh oh- Chatter invading the FP parts? ;-)
Machiavelli said "if an injury has to be done to a man it should be so severe that his vengeance need not be feared."
Is that what you're advocating? If so, he was refering to individuals not entire populations and he used that word "if" for a reason. Certainly he did not advocate occupying or conducting Stalinist purges, rather selectively injuring a few to set an example while allowing the elite to continue to rule without injury. if you purge the elite then you have to occupy and take responsibility for the people, which is expensive.
If your preferred alternative is to smite, then who will you smite?
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1