Is there any proverb or idiom in English that says that "If you understand yourself and your opponent, you can win any battles"?

Question

There is a Chinese proverb saying that "If you understand yourself and your enemy, you can win any battles"?

It seems that the proverb was from "The Art of War" of Sun Tzu

“If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.” (Source)

My question is that, is there any proverb in English that expresses the similar meaning

Maybe "He who sees through life and death will meet with most success". but seem this expression just focus on yourself and does not say that you need to understand the enemy.

So, Is there any proverb or idiom in English that says that "If you understand yourself and your opponent, you can win any battles"?

Answer 1

I think the famous Chinese saying is usually expressed in English as 'Know your Enemy':

• a saying derived from Sun Tzu's The Art of War

(Wikipedia) and (TPS Frequency Dictionary of Mandarin Chinese: A Study Guide)

Answer 2

A common English expression is: "Keep your friends close and your enemies closer"

This is often attributed to Sun Tzu and I always thought it was from Hamlet's Polonius but its actually from the Godfather Part II: https://en.wikiquote.org/wiki/Sun_Tzu