“It's not your enemies who are likeliest to hurt you. It is, always, those you trust.”

“It is the nature of war that what is beneficial to you is detrimental to the enemy and what is of service to him always hurts you.”
In omnibus proeliis expeditionis condicio talis est, ut quod tibi prodest aduersarium noceat, quod illum adiuuat tibi semper officiat.

“An Enemy is a friend who knows too much about you. Remember to keep your enemies close to protect all those who you love.”

“If you want your enemy to trust you in the future, keep the promises you made during bargaining.”

“It takes your enemy and your friend, working together, to hurt you to the heart: the one to slander you and the other to get the news to you.”

“How do I know I can trust you?'

'You can't,' he said bluntly. 'You've got to take it on faith that the enemy of your enemy is your friend.”

“When there is no enemy within, the enemies outside cannot hurt you.”

“Those who have hurt you in the past cannot continue to hurt you now unless you hold on to the pain through resentment.”

“Those who really love you don't mean to hurt you and if they do, you can't see it in their eyes but it hurts them too.”

“Your parents could always hurt you, no matter how old you were.”