唇亡齿寒 (chún wáng chǐ hán): lit. without the lips, the teeth feel the cold ; fig. intimately interdependent
唇亡齿寒
lit. without the lips, the teeth feel the cold ; fig. intimately interdependent
Lose the lips and the teeth feel the cold. For two parties whose fates are tied together, said to the one considering letting the other fall.