Never abandon the possibility of attack. Attack even from a position of inferiority, to disrupt the enemy's plans. This often results in improving one's own position.
We had to fight the enemy without in the Falklands. We always have to be aware of the enemy within, which is much more difficult to fight and more dangerous to liberty.
Your enemy shall ye seek; your war shall ye wage, and for the sake of your thoughts! And if your thoughts succumb, your uprightness shall still shout triumph thereby!
So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.