проТивника
know your enemy (?)

Know your enemy when you see him/her. (?)

🙄

Is that a yes or a no?

I don't kown. 😁

Oh it doesn’t make sense in russian?

It really does))

знать в лицо = знать очень хорошо (буквально - знать, как выглядит)
В reverso - просто know your enemy
https://context.reverso.net/translation/russian-english/знать+в+лицо

Praemonitus, praemunitus.

Противника надо знать в лицо is commonly used as a slogan of lectures on AIDS, for example.

Чтобы человечество не вымерло от СПИДа, мы должны знать противника в лицо.

In that case, it can be simply KNOW YOUR ENEMY, and if you want to express как выглядит, then add WHEN YOU SEE HIM. They both make sense here.

👍🙏