Sun Tzu's Art of War is a great handbook for fighting a war, but if you try to apply away from the battlefield, towards the inner workings of government all you will end up with is a Macivellian tyranny.
What about applying it to business? I see SOME parallels, but obviously we can't apply everything.
The key to applying the type of generalized rules that Sun Tzu laid out is knowing when they apply and when they don't. Once having identified that, one then has to apply a proper response. The application of Sun Tzu in the business place does not result in tyranny, but rather the mis-application, IMHO.
As for Machiavelli, he never advocated tyranny, but was simply one of the most astute observers of human nature that has ever put pen to paper since Aristotle.