Kill with a Borrowed Sword
When you do not have the means to attack your enemy directly, then attack using the strength of another. Trick an ally into attacking him, bribe an official to turn traitor, or use the enemy's own strength against him.
Warring States Era China
Chang Tuo defected from Western Zhou and went to Eastern Zhou where he revealed all of Western Zhou's state secrets. Eastern Zhou rejoiced while Western Zhou was furious. Minister Feng Chu said to the king of Western Zhou: "I can assassinate that man if your highness will give me thirty catties of gold." The king consented and the next day Feng Chu sent an agent to the Eastern Zhou court bearing the gold and a letter addressed to Chang Tuo. The letter read: `This is to remind Chang Tuo that you must complete your mission as soon as possible for the longer the delay the more likely you will be found out.' Before the first agent departed, Feng Chu then sent another agent to the Eastern Zhou border guards informing them that a spy would be crossing the border that night. When the second agent arrived at the border he was stopped and searched. The border guards found the gold and the letter to Chang Tuo and turned them over to the Zhou court officials. Shortly afterwards Chang Tuo was executed.