井陉口 / Jingxing Pass

井陉口 / Jingxing Pass first appears implicitly through Qinji 129-2, where 王离 blocks 李良 on the Jingxing route toward Taiyuan. That earlier notice already makes Jingxing a military movement gate rather than a neutral road.

Hanji 156 part 1 turns it into the central terrain problem for 韩信’s Zhao campaign. The episode identifies Jingxing as one of the Taihang passes and as an important route from today’s Shanxi into Hebei. Its road is narrow enough that horses cannot travel side by side, making a long army vulnerable to ambush and supply disruption.

For 赵国, Jingxing gives 陈馀 and 赵歇 a defensive advantage. For Han Xin and 张耳, it turns forward movement into a logistics and formation problem: the force must exit a dangerous pass with supplies trailing behind. 李左车’s rejected plan depends on exactly this geography.

Hanji 156 part 2 turns that terrain problem into the completed 背水一战. Han Xin exits the pass only after learning through spies that Chen Yu has rejected Li Zuoche’s plan, sends hidden cavalry ahead near the eastern mouth, and uses the river-side formation to make Zhao leave its camp. Jingxing therefore becomes both the chokepoint that endangered Han and the entry gate for Han Xin’s trap.

Hanji 157 part 1 makes the pass a precondition test. Han Xin’s spies do not only report Chen Yu’s strategic choice; they also let him know that the narrow road has not been turned into an ambush. That information is what lets Jingxing shift from a possible logistical trap into the controlled setting for 死地战术前提.

Connections

• 太行道 - broader route frame to which Jingxing belongs.
• 韩信, 张耳, 陈馀, 赵歇, and 李左车 - actors whose options are shaped by the pass.
• 王离 and 李良 - earlier Qin-collapse use of the same route as a movement constraint.
• 交通线切割, 战场围困与断粮, 战场信息控制, and 背水一战 - concepts connected to the pass’s supply, ambush, movement, and completed battle consequences.
• 死地战术前提 - Hanji 157 part 1 reading of the pass as a risk that must be verified before backwater commitment.