An entire chapter on the use of espionage and deceit against enemy commanders, to be precise. Machiavelli wrote more than one chapter on the art of backstabbing your nominal allies, but Sun-Tzu didn't touch the subject.
Yeah, yeah. I'm just saying, your friends' bodies lie face-down on the dirt in front of where you stand, bloody knife in hand, gleefully comparing yourself to Sun-Tzu. Please. Trusting you - or anyone else in this and any other such game, for that matter (but especially you), - that far was always a very bad play to begin with, to be sure. Props for successfully hammering through what I was trying real hard to tell people about trusting you from the start, but uh. You've got your books wrong, is what I'm saying.
The Art of War is guide material for dealing with full opposition in open war, from the general protips to some down-and-dirty managerial specifics; The Prince is about recognizing and seizing the various advantages and demerits inherent in the politics behind it. That's the one which openly explores in depth, and condones to no small extent, a myriad set of hypothetical and historical cases in which screwing over your allies for your own benefit is objectively totally worth it, how best to do so, and why.
I'm just tryna help you gloat more properly is all.