Common-Enemy Alliance / 共同敌人联盟

Common-enemy alliance / 共同敌人联盟 is the alliance-building pattern 《资治通鉴·周纪》30丨苏秦的“开挂”人生 draws from 苏秦’s first successful diplomatic task. After 燕文公 funds him, Su Qin’s job is to make 燕国 and 赵国 align; the episode closes by saying that a shared enemy can matter more than shared interest.

In the source case, the enemy pressure is 秦国. Su Qin persuades Yan Wen Gong that Yan has remained safe because Zhao functions as a geographic shield, making Zhao’s survival and friendliness part of Yan’s own security. The concept therefore turns alliance from abstract friendship into threat geometry.

《资治通鉴·周纪》31丨合纵连横 围殴秦 broadens the same logic from Yan-Zhao relations to the proposed six-state 合纵. Su Qin tells 赵肃侯 that Qin is the one enemy strong enough to make the eastern states’ separate fears converge, but the alliance still needs hostages, rescue duties, and punishment clauses because a shared enemy does not automatically create trust.

《资治通鉴·周纪》32丨“史上首位联合国秘书长”苏秦 shows the same shared-enemy logic being sold state by state. 苏秦 adapts the Qin threat to Han’s land limits, Wei’s military capacity, Qi’s urban confidence, and Chu’s final coalition position, so the common enemy becomes locally persuasive rather than merely abstract.

Key Claims

• Shared interest can be too vague to bind actors; shared threat can clarify urgency and direction.
• A buffer state can become valuable not because it is loved, but because it absorbs or redirects a stronger enemy’s pressure.
• The pattern helps explain how 合纵 can begin from bilateral security logic before becoming a broader anti-Qin coalition claim.
• The source keeps the lesson practical rather than moral: fear and survival can produce cooperation where goodwill cannot.
• A common enemy can create direction, but it still needs institutional enforcement when allies suspect each other.
• A shared enemy becomes stronger as rhetoric when each state can see how Qin pressure specifically threatens its land, face, prestige, or security role.

Connections

• 苏秦, 燕文公, 赵肃侯, 燕国, and 赵国 - source cases.
• 秦国 and 秦国东进压力 - shared threat and broader pressure frame.
• 合纵, 连横, and 纵横家外交 - larger coalition, rival strategy, and persuader-diplomacy setting.
• 揣摩 - audience-and-situation reading needed to identify the usable common enemy.
• 尊严激将式说服, 临淄, and 战国军事形态转变 - Zhouji 32 local evidence used to make the shared enemy persuasive.