Territorial Control Churn / 城池反复易手
Territorial control churn / 城池反复易手 is the pattern 《资治通鉴·周纪》07丨两起刺杀（2） illustrates through 负黍. A city can be seized, defect back, and then be taken by a third state within a short span, making control look temporary rather than settled.
The concept supports the episode’s broader claim that early 战国时期 warfare is accelerating. It is related to Small-State Buffer Diplomacy / 小国夹缝外交, but the scale is different: buffer diplomacy explains why a state like 郑国 is squeezed by great powers, while territorial churn shows how that pressure appears on the ground as cities and borderlands repeatedly change hands.
《资治通鉴·周纪》09丨战国时代的世界大战 adds 中山国 as a frontier-control case. Wei had held Zhongshan as a detached territory through 魏挚, but wartime distraction lets Di forces drive Wei Zhi out and allows Zhongshan to revive.
Key Claims
- City control in a high-conflict interstate system can be provisional.
- Defection matters alongside formal conquest; local allegiance can change the map.
- Repeated transfer is evidence of weakening state control, not only battlefield success by rivals.
- A single city can become a diagnostic case for larger war tempo and state capacity.