To combat an adversary, become their friend.

A soldier will fight long and hard for a bit of colored ribbon.

It pays to know the enemy - not least because at some time you may have the opportunity to turn him into a friend.

a soldier lives always for the next battle, because he knows that before it arrives impossible changes can occur in his favor.

Fortune befriends the bold.

You seek up a big monster for him to fight your wars for you.

He will win who, prepared himself, waits to take the enemy unprepared.

Imperator Caesar Augustus: don't you ever worry! You will always have gladiators. And you will have more than you will ever need. The strongest, the finest, the bravest men will be your gladiators; they will fight for you, and dying they will hail you: Morituri te salutamus! Hail, Cæsar Augustus! The moribund are greeting you. Happy? I am the happiest man on earth to have the honor to fight and to die for you, you god Imperator.

A faithful friend is a strong defense;
And he that hath found him hath found a treasure.

He who is prudent and lies in wait for an enemy who is not, will be victorious.

War comes and goes but a soldier stays eternal

Do good to your friend to keep him, and to your enemy to make him your friend.

Aziraphale. The Enemy, of course. But an enemy for six thousand years now, which made him a sort of friend.

Fortune assists the Bold, the Valiant Man
Oft Conqueror proves, because he thinks he can.