To have a good enemy, choose a friend; he knows where to strike

Courage is as often the outcome of despair as of hope; in the one case we have nothing to lose, in the other, everything to gain

The enemy hidden behind a face of friendship is more dangerous than the enemy who wants to fight us in a direct way.

And this was your friend?" Cordelia raised her eyebrows. "Seems to me the only difference between your friends and your enemies is how long the stand around chatting before they shoot you.

Enemies disguise as friends and friends as enemies.

I suppose [...] that the most convincing way to fool an enemy would be to fool a friend.