"He who is skilled in attack flashes forth from the topmost heights of heaven, making it impossible for the enemy to guard against him.

This being so, the places that I shall attack are precisely those the enemy cannot defend...

He who is skilled in defence hides in the most secret recesses of the earth, making it impossible for the enemy to estimate his whereabouts.

This being so, the places that I shall hold are precisely those that the enemy cannot attack."

- Sun Tzu, The Art of War