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concept Updated 2026-08-25 Topics: History, Politics

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.

《资治通鉴·周纪》45｜以史为鉴，君王到底该不该杀人成性？ adds the failure mode. In the 318 BCE anti-Qin campaign, the eastern states share Qin as the enemy and reach 函谷关, but each state tries to preserve its own army and avoid attacking first. The episode turns that into 联盟自保失灵: a common enemy supplies direction, not trust or cost-sharing.

《资治通鉴·周纪》46丨骂你是个“二百五”的历史来源 adds the cost of that failed trust conversion. Once the Hangu Pass coalition withdraws, 秦国 can pursue 韩国 and 魏国 to 修鱼之战 and 浊泽. A shared enemy that does not create shared sacrifice can leave some allies carrying the retaliation more directly than others.

《资治通鉴·周纪》50丨张仪是怎样把楚怀王忽悠瘸的 adds the separation tactic. 齐国 and 楚国 are valuable to each other because each helps block 秦国, but 张仪 uses a promised 商於 transfer to make 楚怀王 treat private gain as more urgent than the common enemy. Once Chu insults Qi, the shared-enemy structure breaks before Qin has to fight it.

《资治通鉴·周纪》54丨我尊你是王，你当我是屁 adds the aftermath rhetoric. Zhang Yi’s speeches to Qi and Zhao assume that common-enemy coordination has already been weakened: if Chu, Han, Wei, and Zhao can be described as Qin-facing or Qin-usable, then the remaining ruler is pressured to defect before being isolated.

《资治通鉴·周纪》69丨必看！古代帝王奇葩死法大盘点 adds an anti-Qi version rather than another anti-Qin one. 燕昭王 wants revenge, but 乐毅 argues that 燕国 cannot safely defeat 齐国 alone. Qi Min Wang’s post-Song arrogance and attacks give Zhao, Chu, and Wei enough shared grievance to join, so the common enemy becomes 齐湣王 rather than Qin.

《资治通鉴·周纪》70丨喜欢花样作死的齐国君主 shows that common-enemy coordination can be enough to win the first campaign without making the allies identical. After Qi’s army is beaten, Le Yi sends 秦国 and 韩国 home because they cannot easily occupy Qi territory, assigns nearer gains to 魏国 and 赵国, and keeps 燕国 moving toward 临淄. The common enemy binds the attack, but post-victory geography and spoils still divide the work.

《资治通鉴·周纪》73丨历史上自由恋爱的开创者是谁？ adds the consequence of that division. Qin’s later attack on Wei after being compensated with wealth shows that common-enemy victory can produce post-coalition spoils imbalance: the war can be won while the payoff distribution leaves a strong ally looking for land or leverage elsewhere.

Hanji 950 adds the formation moment for the anti-董卓 version. Dong Zhuo’s violence makes Guandong commanders raise armies and accept 袁绍 as盟主, but 郑泰 already argues that the participants lack unified hierarchy, practical military confidence, and shared interests. The common enemy can convene the field before it can discipline it.

Hanji 953 adds the early anti-董卓 action version. Dong Zhuo’s violence gives the coalition an obvious common enemy, but 曹操 is the only actor willing to test the line after Luoyang burns and the emperor is moved west. The Suanzao armies’ refusal to implement Cao Cao’s later pass-control plan shows that a common enemy can clarify opposition without creating shared risk, supply, or command.

Hanji 954 adds the title-coordination problem before the coalition’s battlefield and office conflicts. 董卓 is the common enemy, but the coalition cannot agree on what to do with the 汉献帝 title while Dong Zhuo controls it. 曹操 insists that the common-enemy campaign needs the recognized emperor as its public basis, while 袁绍 and 韩馥 try to replace that basis through 刘虞.

Hanji 955 adds a front-line late-Han version before Hanji 958’s coalition-collapse frame. 董卓 supplies the common enemy, and 孙坚 produces real battlefield pressure against him, but 袁术 still cuts Sun Jian’s grain out of fear that success will make the ally uncontrollable.

Hanji 958 adds a late-Han version through the 反董卓联盟. 董卓 is strong enough to provide a shared enemy, but the coalition does not create stable trust among 袁绍, 袁术, 孙坚, and 公孙瓒. The result is a common-enemy front that fractures before its stated enemy is removed.

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.
  • A common enemy can still fail as strategy when every ally wants someone else to pay the first cost.
  • The aftermath can be asymmetric: the states nearest the enemy’s counterattack may suffer most once the coalition breaks.
  • A common-enemy alliance can also be broken before battle if one member accepts an unverified private reward for abandoning the shared front.
  • After a common-enemy alliance looks broken, its failure can itself become a persuasion weapon for further defections.
  • A state that recently used coalition politics against others can itself become the common enemy if victory turns into overreach.
  • A common enemy can align the campaign while still leaving each ally with different occupation capacity, payoff, and withdrawal timing after the first victory.
  • The post-victory payoff can become a new conflict trigger if a strong ally treats treasure as inadequate compensation.
  • Hanji 953 adds that a common enemy can identify the target while still failing to allocate first risk, logistics, and command.
  • Hanji 950 adds that a common enemy can assemble a coalition and leader before it creates military discipline, shared hierarchy, or durable trust.
  • Hanji 955 adds that even the coalition’s most effective battlefield actor can become suspect to his own supplier before the common enemy is defeated.
  • Hanji 958 adds that a common enemy can fail even before victory, when participants are already pricing offices, rear bases, and troop flows against one another.

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