A Kingdom at the Crossroads

In 246 BCE, the Qin state stood poised between greatness and paranoia. Under the young King Ying Zheng (later First Emperor of China), Qin had emerged as the most powerful of the Warring States, its legalist reforms and military might making it the likely unifier of China. Yet this pivotal moment saw one of history’s most dramatic policy reversals – the infamous “Expulsion of Foreigners” decree that nearly derailed Qin’s rise to empire.

The crisis centered around two remarkable figures: Li Si, the Chu-born legalist scholar who would become Qin’s chancellor, and Zheng Guo, the Korean hydraulic engineer whose monumental irrigation project became entangled in international intrigue. Their intertwined fates reveal the tensions between Qin’s outward-looking ambitions and inward-looking suspicions during this transformative era.

The Waterworks Conspiracy

The crisis began with what appeared to be an engineering marvel. Zheng Guo, a master water engineer from Han, proposed an ambitious project to divert the Jing River through the Hukou Gorge, creating an irrigation network that would transform Qin’s arid northwest into fertile farmland. King Zheng enthusiastically approved, appointing Li Si as project supervisor.

For years, thousands of laborers toiled under Li Si’s direction, carving channels through solid rock. The scale was staggering – a thirty-li (15km) canyon being transformed into what should have been an agricultural lifeline. Then came the shocking revelation: Zheng Guo was allegedly a Han spy, sent to exhaust Qin’s resources through this massive undertaking, preventing Qin from attacking other states.

The discovery triggered panic at court. Conservative Qin nobles, long suspicious of foreign influence, seized the moment. In 237 BCE, the king issued the infamous expulsion order, demanding all non-Qin officials and merchants leave within ten days. The decree specifically named Zheng Guo alongside disgraced former ministers Lü Buwei and Lao Ai as examples of foreign treachery.

The Abandoned Canyon

Li Si’s return to the Hukou worksite as a prisoner marked one of history’s great anticlimaxes. The once-bustling canyon now stood eerily silent, littered with abandoned tools and makeshift shelters. White and black boulders loomed like ghosts in the abandoned diggings. The military commander sent to enforce the expulsion, Ying Teng, treated both Li Si and Zheng Guo with shocking brutality, despite their years of service.

Most telling was the reaction of Qin’s common workers. Unlike officials who cheered the expulsion, the laborers who had sacrificed for the project departed in stunned silence. Their mute disbelief spoke volumes about the disconnect between court politics and practical governance. Zheng Guo’s emotional breakdown upon seeing his life’s work abandoned remains one of ancient China’s most poignant moments.

Li Si’s Exile and Defiance

Back in Xianyang, Li Si found himself abruptly dismissed. The bureaucratic machine processed him with cold efficiency – given a horse and ten pieces of gold, ordered to leave Qin within two days. Even attempting to say farewell to friends was discouraged as potentially “implicating the innocent.”

The once-vibrant international quarter of Shangfang Market, where merchants from all states had thrived, now stood desolate. Only a bold young attendant at an abandoned Qi merchant house dared offer Li Si shelter, boasting that his employer saw the expulsion as Qin’s folly and was secretly welcoming displaced talent.

It was here, drinking by moonlight on a boat in the merchant’s pond, that Li Si composed his legendary “Petition Against Expelling Guest Officials.” Writing with furious precision on a rocking vessel, he crafted what would become one of Chinese history’s most celebrated statecraft documents. His arguments were pragmatic rather than moral: great rulers utilize talent regardless of origin; Qin’s rise depended on foreign advisors from its earliest days; rejecting outside expertise would cripple the state’s ambitions.

The Cultural Fault Lines

The expulsion crisis revealed fundamental tensions in Qin’s identity. The state’s remarkable success had come through embracing foreign ideas – from Shang Yang’s reforms to the military strategies of Wei-born advisors. Yet its warrior aristocracy remained deeply suspicious of outside influence, particularly after scandals involving foreign-born ministers.

Li Si’s petition brilliantly reframed the issue as one of state interest rather than cultural purity. By listing all the foreign-born officials who had contributed to Qin’s rise, he forced the king to confront an uncomfortable truth: Qin’s strength came from being a meritocracy in a world of hereditary privilege. The expulsion order, far from protecting Qin, would strip it of its greatest competitive advantage.

Legacy of a Crisis

The aftermath proved Li Si right. King Zheng rescinded the expulsion order, bringing Li Si back as a key advisor. Zheng Guo was allowed to complete his irrigation project, which ultimately benefited Qin despite its suspicious origins. The Hukou canal system became a cornerstone of Qin’s agricultural base, supporting its eventual conquest of China.

Historically, the episode marked a turning point. Qin doubled down on its cosmopolitan approach, with Li Si overseeing the standardization of Chinese script, laws, and measurements – policies that enabled imperial unity. The crisis also demonstrated the power of reasoned argument in Chinese statecraft, with Li Si’s petition becoming a model for ministerial remonstrance.

Yet the tensions never fully disappeared. Even after unification, Qin’s distrust of scholars would lead to the infamous “Burning of Books and Burying of Scholars.” The delicate balance between openness and control, between utilizing talent and maintaining security, remains a challenge for governments to this day. The expulsion crisis of 237 BCE thus stands as both a dramatic historical moment and a timeless case study in statecraft.