Brief: This article analyzes Cao Cao’s masterful psychological warfare during the Battle of Tong Pass in the Three Kingdoms era. It details how Cao Cao exploited the alliance between warlords Ma Chao and Han Sui through a series of calculated deceptions. By orchestrating a fake friendship, a staged meeting, and a forged letter filled with suspicious edits, Cao Cao sowed deep seeds of mistrust between the two leaders. This narrative highlights how Cao Cao’s strategist, Jia Xu, utilized the “sowing discord” tactic to fracture their coalition from within. Ultimately, the article illustrates how Cao Cao secured a decisive victory not merely through superior arms, but by manipulating human weakness and division.
The strategic backdrop
The Guanxi (Guanzhong and Liangzhou) region had long been under the control of two powerful warlords: Ma Teng and Han Sui. Ma Teng, a descendant of the famed Eastern Han general Ma Yuan, commanded deep loyalty among the frontier troops.
Before launching his southern campaign against Jingzhou (Jing Province), Cao Cao – now de facto ruler of the Han court – sought to neutralize this western threat. In a calculated move, he summoned Ma Teng to the capital and appointed him Minister of the Guards (Weiyi), a prestigious but powerless post. In reality, Ma Teng and over 200 family members, including two of his sons, were held as hostages in Yecheng (Ye City).
Command of Ma Teng’s forces passed to his eldest son, Ma Chao, who joined forces with Han Sui to govern the west.
After his defeat at Red Cliffs (AD 208), Cao Cao turned his attention westward. To justify military action and provoke rebellion, he ordered Zhong Yao to attack Zhang Lu in Hanzhong and directed Xiahou Yuan to march through Guanzhong. This “fishing strategy” successfully alarmed Ma Chao and Han Sui, who interpreted it as a prelude to annexation. Their subsequent uprising in AD 211 played directly into Cao Cao’s hands – giving him a legitimate pretext to crush the coalition.
The battle of Tong Pass
Ma Chao and Han Sui swiftly mobilized 100,000 troops and seized Tong Pass, a strategic chokepoint where the Wei River meets the Yellow River in modern-day Shaanxi.
Upon hearing of their revolt, Cao Cao retaliated by imprisoning Ma Teng and his entire family – a brutal but effective deterrent. With Zhou Yu, the one who once defeated him in the Red Cliffs, recently dead and Eastern Wu temporarily quiescent, Cao Cao marched west without fear of a two-front war.
His advisors warned:
“Guanxi warriors are fearless, expert with long spears. We must lead with our elite vanguard!”
But Cao Cao scoffed:
“War is decided by me, not by their spears. Wait and see.”
He arrayed his army along the south bank of the Wei River, directly facing the rebel forces on the north.
A narrow escape, A clever diversion
Instead of attacking head-on, Cao Cao sent Xu Huang and Zhu Ling with 4,000 elite troops on a wide flanking maneuver behind enemy lines. He then began ferrying his main force across the river.
As the bulk of his army crossed, Cao Cao remained on the south bank with only 100 guards. Ma Chao seized the moment, rushing 10,000 cavalry to the riverbank and unleashing a hail of arrows.
Cao Cao sat calmly in his chair until Xu Chu, his loyal bodyguard, swept him onto a boat. With the boatman slain, Xu Chu used a saddle as a shield and rowed with one hand, saving his lord.
Just as Ma Chao’s men closed in, a herd of cattle and horses suddenly stampeded across the southern plain. Undisciplined and greedy, the rebel soldiers abandoned pursuit to loot the animals. The diversion – orchestrated by Colonel Ding Fei – allowed Cao Cao to escape unharmed.
Cao Cao rewarded Ding Fei and regrouped at Weinan, now behind enemy lines. Although, Ma Chao achieved a tactical victory in the battle of Tong Pass (Tongguan), Cao Cao had already won the strategic game, with his army now west of the Yellow River.
The seeds of mistrust are planted
Ma Chao launched a night raid on Cao Cao’s camp – but walked into a trap. Surrounded and decimated, he barely escaped. Humiliated, he and Han Sui proposed surrender and territorial compromise.
Cao Cao refused outright – but his strategist Jia Xu whispered a new plan into his ear. Cao Cao laughed: “Perfect! Let’s do it.”
The next day, Cao Cao rode alone to the front lines and called for Han Sui. The two old friends met, reminiscing warmly about past days, laughing and clapping each other on the back. To Ma Chao – watching from afar – it looked like secret collusion.
When Ma Chao demanded to know what was discussed, Han Sui replied innocently:
“Just old friends catching up.”
Suspicion took root.
The forged letter
Days later, Cao Cao sent Han Sui a letter filled with deliberate erasures and blacked-out passages. When Ma Chao saw it, he concluded:
“Han Sui altered the letter to hide his betrayal!”
In truth, the letter was crafted by Jia Xu precisely to appear suspicious. Ma Chao – impulsive and distrustful – never questioned the ruse.
Their alliance, once formidable, now cracked from within.
Defeat through division
Soon after, Cao Cao’s forces issued a challenge. Believing it a minor skirmish, Ma Chao attacked without consulting Han Sui. He initially routed the enemy – but fell into a carefully laid ambush. As Cao Cao’s hidden troops surged from all sides, Ma Chao’s army collapsed.
Han Sui, wounded by Ma Chao’s mistrust, offered no aid. The coalition shattered. That is how Cao Cao shattered the Ma Chao – Han Sui alliance effortlessly.
Ma Chao fled to Liangzhou (modern Gansu), his power broken. Cao Cao had won – not just by arms, but by exploiting human weakness.
As recorded in the Records of the Three Kingdoms (Sanguozhi), this campaign exemplified Cao Cao’s mastery of psychological warfare:
“To defeat an army of ten thousand, first divide its generals.”
Note
Cao Cao
Ruler of northern China, a master of psychological warfare. He used deception and distrust to destroy enemies without major fighting.
Ma Chao
A fierce frontier warlord, son of Ma Teng. He rebelled to save his family but was easily tricked by Cao Cao.
Han Sui
Ma Chao’s ally and old friend of Cao Cao. He was framed by a fake letter and became distrusted by Ma Chao.
Jia Xu
Cao Cao’s top strategist who invented the sowing discord plan to break the alliance.
Ma Teng
Father of Ma Chao, held hostage by Cao Cao in the capital to control the western army.
Xu Chu
Cao Cao’s bodyguard who saved him from death by arrow fire at the Wei River.
Battle of Tong Pass (211 CE)
A decisive campaign where Cao Cao defeated the western warlord alliance using divide and conquer.
Sowing Discord (sow distrust)
A classic tactic: making allies suspect each other until they break apart.
Forged Letter Tactic
A letter with intentional blurs and deletions to make the receiver look guilty.
Hostage Politics
Holding an enemy’s family in the capital to force obedience.
Divide and Conquer
The core military principle: defeat a united enemy by splitting them first.
A fake meeting, a real trap
Cao Cao’s friendly chat with Han Sui was designed to arouse Ma Chao’s suspicion.
Altered letter breaks an alliance
The forged letter became the most famous example of using paperwork to cause betrayal.
Victory without fighting
Cao Cao won mainly by trickery, not by soldiers’ strength.
Distrust is the deadliest weapon
The moral of the story: suspicion destroys even the strongest alliance.
Leave a Reply