School of Diplomacy

The School of Diplomacy (simplified Chinese: 纵横家; traditional Chinese: 縱橫家; pinyin: zōng héng jiā), or the School of Vertical and Horizontal Alliances refers to a set of military and diplomatic strategies during the Warring States period of Chinese history (476-220 BCE), aiming for power balance among the strongest Qin State and the other weaker states. According to the Book of Han, the school was one of the Nine Schools of Thought (Chinese: 九流; pinyin: Jiǔ Liú). Originated by Guiguzi, the School of Diplomacy's main adherents were Gongsun Yan, Su Qin, Zhang Yi, Gan Mao, Sima Cuo, Yue Yi, Fan Sui, Cai Ze, Zou Ji, Mao Sui, Li Yiji and Kuai Che as detailed in the Annals of the Warring States.

By the time of the Warring States period, the major contest was between the powerful State of Qin situated in the west, and the other six mid-power, namely Yan, Zhao, Wei, Qi, Chu, and Han. The seven states engaged in a complex series of pacts and military alliances, commonly referred to as the Horizontal Alliance and Vertical Alliance, based on two geographic patterns. The Horizontal Alliance (连横, liánhéng), adopted by Qin, followed a west-east alignment aimed at curbing the coalitions of the other six states. In contrast, the Vertical Alliance (合纵, hézòng) formed a north-south alignment among the six states to block Qin’s further expansion. The spokesperson for the Vertical Alliance is Su Qin, while the spokesperson for the Horizontal Alliance is Zhang Yi.

According to the Han Feizi, a Pre-Qin text on Legalist Philosophy, The Vertical Alliance refers to multiple smaller states forming an alliance to collectively counter a superpower, whereas the Horizontal Alliance sees a superpower allying with one of its weaker adversaries to divide and weaken the opposition, enabling it to defeat them individually. In practice, Qin successfully broke apart the anti-Qin Vertical Alliances, conquered the smaller states and eventually rise to domination by the middle of the third century B.C. The diplomatic schemes adopted by Qin include lies, bribery, and espionage.

The school's adherents were an active group of diplomats or persuaders who traveled "tirelessly from state to state", trying to lobby the rulers into one or the other alliances. They did not lock their loyalty to any certain state, and instead, would be collecting ministerial seals simultaneously from multiple states with their mastery of persuasive skills. The anecdotes and rhetoric of these travelling advisers were recorded in the Annals of the Warring States, which, as Watson put it, offers "dubious historical value" as legends and eloquent amplification obscured historical facts.