All warfare is based on deception. Hence, when we are able to attack, we must seem unable; when using our forces, we must appear inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near.

Sun-Tzu (fl. 6th C. AD) Chinese general and philosopher [a.k.a. Sun Wu]

The Art of War, ch. 1

Alt trans.: "A military operation involves deception. Even though you are competent, appear to be incompetent. Though effective, appear to be ineffective."