Su Dai sent a messenger from Qi to King Zhao of Yan with a letter, saying: “I have heard that an enlightened ruler must understand his own faults, and is unwilling to hear only of his merits. Allow me to speak of your faults. Qi has long been your enemy, and so I previously sought to ally with Zhao, but you did not respond. Let me finish my words. I have heard that Qi possesses a fine hunting dog, and Yan has a southern gate—allow me to try this metaphor. Qi has defeated Chu in the south, bent Qin to its will in the west, and with its armies, controlled Han and Wei in the south, and Zhao in the north—yet Yan alone does not come to pay homage. Qi will surely resort to force against it. Now, if Your Majesty truly wishes to take revenge on Qi, I beg you to make Zhao an external ally and Qi an internal correspondent. I request to go on your behalf as an envoy to Qi, and Qi will certainly trust me. I shall use the pretext of allying with Zhao, and Qi will surely grow angry; in its anger, it will surely attack Zhao, and Zhao will surely unite with Yan. In this way, Qi can be broken. This is what I mean by the strategy of the ‘northern dog and southern gate.’ Let Your Majesty harbor no doubt, and allow me to decide this matter.” Thereupon King Zhao of Yan sent Su Dai to Qi. Upon arriving in Qi, Su Dai persuaded King Min of Qi, saying: “I have heard that Qi has defeated Chu in the south, bent Qin to its will in the west, and with its armies, controlled Han and Wei in the south, and Zhao in the north—yet Yan alone does not pay homage. This is not to Your Majesty’s advantage. Now King Zhao of Yan is worthy, and all the feudal lords wish to befriend him. It would be better for Your Majesty to foster good relations with Yan, making Yan the Eastern Emperor and Qi the Western Emperor. Then Yan will surely be grateful to Your Majesty, and Qi can be at peace. If Your Majesty does not befriend Yan, Yan will surely ally with Zhao; if Zhao grows strong, Qi will be in peril. It would be better for Your Majesty to set aside Yan and serve Zhao; Zhao will surely heed Your Majesty, and then Yan will not dare to disobey either—this is Your Majesty using Zhao to restrain Yan.” King Min of Qi said: “Well said.” Thereupon he did not attack Yan, and Yan found tranquility. Su Dai returned to Yan, and King Zhao of Yan asked: “Can Qi be broken?” Su Dai replied: “It can. I have already caused Qi not to attack Yan, but Qi’s counselors will all grow suspicious; the King of Qi will surely become arrogant, and arrogance will surely lead to negligence. I request to use schemes to sow discord among them.” Later, Qi indeed grew arrogant, and Yan ultimately broke Qi.
💡 商战启示录
Su Dai's strategy stands as a classic exemplar of the ancient arts of "sowing discord" and "borrowing force to deflect force." He began by employing the metaphor of "a northern hound at the southern gate" to counsel King Zhao of Yan, proposing that Yan exploit Qi's arrogance by luring it into attacking Zhao, thereby compelling Zhao to forge an alliance with Yan—a strategic coalition reminiscent of the principle "besiege Wei to rescue Zhao." In the modern arena of commerce, this mirrors the "vertical and horizontal alliances" forged between enterprises. For instance, when an industry titan (such as Apple) aggressively suppresses its rivals, weaker players (like Huawei or Xiaomi) may temporarily unite, or exploit the giant's hubris to steer it toward misguided expansion, thereby dispersing its resources. Su Dai's persuasion campaign in Qi, meanwhile, showcases the arts of "information manipulation" and "psychological warfare"—he deliberately sowed suspicion between the King of Qi and his counselors, fostering the king's arrogance until internal discord brought about his downfall. This parallels business negotiations, where releasing misleading information leads opponents to overestimate their own strengths and underestimate latent risks, lulling them into strategic complacency. Modern enterprises such as Nokia, which once dismissed the Android system out of self-assurance and was subsequently overtaken by the combined forces of Apple and Samsung, serve as a vivid testament to the adage that "the arrogant army is destined for defeat." The core lesson of Su Dai lies in this: within any competitive landscape, one need not assault head-on; rather, one should adeptly exploit an opponent's weaknesses through diplomatic maneuvering, alliance strategies, and psychological tactics to achieve victory from a position of apparent weakness. At the same time, one must remain vigilant against the "information cocoon"—the King of Qi trusted only Su Dai's one-sided counsel, leading to flawed decisions, just as a corporate leader who heeds only a single source of information may fall into strategic blind spots. A true master of commercial warfare must, like Su Dai, understand both how to "ride the momentum" and how to "create the momentum," seeking the fulcrum of leverage within the dynamic interplay of competition.