Clamor in the East, Attack in the West
In any battle the element of surprise can provide an overwhelming advantage. Even when face to face with an enemy, surprise can still be employed by attacking where he least expects it. To do this you must create an expectation in the enemy's mind through the use of a feint.
Song Dynasty China
Once there was an official who was transferred to the capital. The front part of the inn where he stayed was a teahouse, and across the street was a shop that sold expensive dyed silks. Whenever he had nothing to do, he would sit at a table watching the people and activity on the street. One day he noticed with surprise that several suspicious looking characters were walking back and forth observing the silk shop with great interest. One of them came up to his table and whispered: "We're in the robbery business and we're here to steal those fine silks. Since you noticed us I came to ask you not to mention it." "That has nothing to do with me," the official replied. "Why should I say anything about it?"
The fellow thanked him and left him. The official thought to himself: "The silk shop has its wares openly displayed on a busy street. In broad daylight, with a thousand eyes watching, if they have the skill to steal those silks, then they must be smart thieves indeed." So he watched carefully to see how they would manage it. But what he saw was only the same people walking back and forth in front of the silk shop. Sometimes they gathered on the left, sometimes on the right. The official sat watching until after sunset when everyone had gone and the shop had closed. "Those fools." said the official to himself. "They were putting one over on me." When he returned to his room to order some food, he discovered that all his belongings were gone.