The Origins of Divide-and-Conquer Warfare

The concept of using division as a military strategy has deep roots in Chinese warfare philosophy. Ancient Chinese military treatises, particularly Sun Tzu’s The Art of War, emphasized psychological manipulation as a key component of battlefield success. Among the “Twelve Methods of Deception” outlined by Sun Tzu, the principle of “divide those who are united” (亲而离之) became a cornerstone of tactical thinking.

This approach recognized that even the most formidable armies could be undermined by exploiting internal tensions. The strategy gained prominence during the Warring States period (475–221 BCE), a time of constant conflict between rival kingdoms. As states vied for supremacy, military commanders increasingly turned to psychological warfare to gain advantages that brute force alone could not achieve.

The Tian Dan Gambit: A Masterclass in Strategic Division

One of history’s most brilliant applications of this strategy occurred in 284 BCE during the siege of Jimo. The context was critical: Yan general Yue Yi had led a coalition force from five states (Qin, Wei, Han, Zhao, and Yan) to devastating victories against Qi, capturing the capital Linzi and forcing King Min of Qi to flee.

Tian Dan, a minor Qi official thrust into leadership during the crisis, faced impossible odds. The Yan forces had reduced Qi to just two strongholds: Ju and Jimo. When the siege of Jimo dragged on for years, Tian recognized his opportunity following the death of Yan’s King Zhao and the ascension of King Hui, who harbored longstanding suspicions about Yue Yi.

Tian executed a three-pronged disinformation campaign:
1. He spread rumors that Yue Yi feared execution if he returned to Yan
2. Suggested Yue Yi was deliberately prolonging the siege to establish his own kingdom in Qi
3. Claimed the Qi defenders feared any Yan general except Yue Yi

The psychological impact was devastating. King Hui recalled Yue Yi, replacing him with the incompetent Qi Jie. This single decision:
– Removed Qi’s most formidable opponent
– Demoralized Yan’s veteran troops
– Created factional divides within the Yan command structure

The Fire Bull Innovation and Decisive Victory

With the Yan forces weakened by internal divisions, Tian Dan prepared his masterstroke—the legendary “fire bull” tactic. Historical accounts describe:
– 1,000 oxen draped in colorful dragon-patterned cloth
– Blades affixed to their horns
– Reeds soaked in oil tied to their tails

Under cover of darkness, Qi forces:
1. Ignited the oxen’s tails
2. Released the panicked animals toward Yan positions
3. Followed with 5,000 elite troops

The result was catastrophic for Yan. The surprise attack broke the siege, and Tian Dan capitalized on the momentum to reclaim over seventy Qi cities in a stunning reversal of fortunes.

Psychological Warfare in the Ancient World

The Jimo campaign demonstrates several enduring principles of divide-and-conquer strategies:
1. Intellegence Utilization: Tian Dan’s spies provided crucial knowledge about tensions between Yan’s new king and his general
2. Timing: The strategy coincided perfectly with a leadership transition in Yan
3. Amplification: Rumors played on existing suspicions, making them more credible
4. Follow-Through: The psychological victory was immediately exploited with tactical innovation

Similar strategies appear in other ancient conflicts. The Thirty-Six Stratagems, compiled later, would formalize these approaches, including:
– “Kill with a borrowed knife” (借刀杀人)
– “Watch the fires burn across the river” (隔岸观火)
– “Remove the firewood from under the pot” (釜底抽薪)

The Bait of War: Cao Cao’s Trap at Yan Ford

Another classic example occurred in 200 CE during the rivalry between Cao Cao and Yuan Shao. At Yan Ford, Cao Cao:
– Purposely abandoned supply wagons
– Had cavalry dismount to appear vulnerable
– Lured Yuan Shao’s forces into disorganized looting

When Yuan’s troops broke formation to plunder, Cao’s 600 cavalry ambushed them, defeating a force ten times their size. This victory set the stage for Cao Cao’s decisive win at Guandu.

Legacy and Modern Applications

These ancient strategies continue to influence modern warfare and geopolitics:
1. Military Deception: Contemporary information operations owe much to these early psychological tactics
2. Corporate Strategy: Business competitors often employ similar divide-and-conquer approaches in market competition
3. Political Maneuvering: The principles appear in election strategies and diplomatic relations

The enduring lesson is clear: physical strength alone rarely guarantees victory. As Tian Dan and Cao Cao demonstrated centuries ago, understanding human psychology and exploiting divisions can overcome even the most daunting material disadvantages. Their campaigns remain case studies in the art of turning an enemy’s strength into weakness through careful observation, precise timing, and bold execution.

The next time you face an apparently stronger opponent, remember the fire bulls of Jimo—sometimes the path to victory lies not in confronting strength directly, but in ensuring it never gets united against you in the first place.