Deception

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 (c. 6th century BC), Chinese general, military strategist, and philosopher, The Art of War, Chapter 1, Detail Assessment and Planning