The art of war. I would say anything by George Orwell but I know for a fact kids are forced to read his shitty fairy tales in high school as a part of their ideological brainwashing
I'm sure it was revolutionary back in the day for warlords to learn that keeping your supply lines defended was important and also you shouldn't fight a battle against an uphill defender with the sun at their back on muddy ground.
I think they're good books, it's just that they're again and again referred to as "proof that communism was horrible" by people who have not the slightest clue how communism actually was besides what the western governments tell them about it
Written by a British imperial cop who doesn't have the slightest clue about the place he's writing about and relies on his own life experience of oppressing Indians for King and Country to fill in the gaps