【Source】Gan Kang (Tang Dynasty), "Presenting a Petition to Qiji"
【Explanation】To watch a fire across the river. It means to remain aloof from a conflict and adopt a stance of passive observation.
【Historical Anecdote】
In 202 AD, Yuan Shao fell seriously ill and soon died. His three sons immediately began a power struggle: the eldest son was excluded, power passed to the second son, and the youngest supported this decision. Naturally, the eldest son refused to accept it, and thus the Yuan brothers began a civil war.
Cao Cao saw their internal conflict as an opportunity and launched an attack. However, his threat prompted the Yuan brothers to set aside their dispute and unite against the external enemy. Cao Cao then withdrew his forces, giving the Yuan brothers more time to deepen their internal conflict. The brothers remained stubborn in their positions, and their war gradually escalated. Over the next three years, Cao Cao skillfully exploited the Yuan brothers' disunity, seizing significant portions of their territory.
In 205 AD, Cao's army attacked and killed Yuan Tan, the eldest son of the Yuan family. By this time, Cao Cao had already occupied most of the Yuan clan's lands. The remaining two brothers, Yuan Xi and Yuan Shang, were forced to flee their homeland and sought refuge with the Wuhuan, a nomadic tribe.
Two years later, in 207 AD, Cao Cao launched an attack against the Wuhuan, who were sheltering the Yuan brothers. After a long and arduous march, Cao's army destroyed the Wuhuan forces and killed their chieftain. The Yuan brothers escaped once again and sought protection under Gongsun Kang, another distant nomadic leader.
After pacifying northern China, Xiahou Dun and other generals urged Cao Cao to attack Gongsun Kang. Cao Cao, however, laughed and said, "There's no need for you all to march again. In a few days, Gongsun Kang will personally send us the heads of the two Yuans." The generals did not believe him. But within days, Gongsun Kang indeed sent an envoy delivering the heads of Yuan Xi and Yuan Shang. The generals were astonished and deeply impressed by Cao Cao's foresight. Cao Cao laughed loudly and said, "Indeed, Guo Jia predicted this!" He then produced a letter left by Guo Jia before his death, which read: "If you hear that Yuan Xi and Yuan Shang have fled to Liaodong, my lord, under no circumstances should you send troops. Gongsun Kang has always feared that after the Yuans are defeated, these two brothers will come to him. If you attack him, they will surely unite to resist you, and you will fail to achieve your goal quickly. But if you wait patiently and make slow moves, Gongsun Kang and the Yuan brothers will inevitably turn against each other."
Indeed, when spies reported back that Cao Cao had no intention of attacking Liaodong, Gongsun Kang immediately executed Yuan Xi and Yuan Shang. Thus, Cao Cao achieved his goal without shedding a drop of blood.
【Life Lesson】
To strive for great victories with minimal effort, one should first observe the internal struggles of the enemy, remain aloof like "watching a fire from the other side of the river," and reap the benefits of a bystander. This is a common tactic employed by skilled strategists. When the enemy's internal conflicts become evident and their mutual hostility intensifies, one must not rush to "take advantage of a fire." Acting too hastily often forces the enemy into a temporary alliance, strengthening their internal cohesion. Instead, if one deliberately holds back and waits for the enemy's internal contradictions to escalate into mutual destruction, one can then sit back and reap the rewards like a fisherman who benefits from the conflict of others.