唇亡齿寒　(chún wáng chǐ hán)

Lips and Teeth

Chinese tend to describe close relations between two neighboring countries as that of lips and teeth. This metaphor is actually derived from a popular idiom Chun Wang Chi Han, or “without the lips, your teeth will be exposed to the chill in the air.”

The idiom is based on a bloody historical event.

During the Spring and Autumn Period (770-467 BC), Duke Jinxian of the State of Jin wanted to annex the neighboring State of Guo.

One of the duke’s officials said the best way to capture the capital of Guo was to launch a surprise attack from the State of Yu, a close neighbor of Guo.

To kill two birds with one stone, the official suggested that the duke ask the ruler of Yu to allow the troops of Jin to pass through his territory and then, after seizing the State of Guo, the Jin troops could easily capture the State of Yu on their way back.

The Duke of Jin liked the plan and decided to follow the official’s advice.

In order to persuade the ruler of Yu to allow the troops to pass through, the Duke of Jin sent a special envoy to the State of Yu and offered the finest jade and his best horse as gifts to the Yu ruler.

A sharp-minded aide in the court of Yu immediately became suspicious. He asked the ruler to decline the presents and reject the proposal of the State of Jin.

The aide said that relations between the State of Guo and the State of Yu were just like those between lips and teeth. Once the lips were no longer there, the teeth would lose protection and be exposed to the chill in the air.

However, the ruler of Yu loved the jade and the horse so much that he turned a deaf ear to the warning and decided to allow the passage of the Jin troops through his territory.

After hearing of the ruler’s decision, the sharp-minded aide gave out a long sigh and fled the state with his family. Before his departure, he told his close friends that the State of Yu would crumble within the year.

The surprise attack launched by the Jin troops proved successful and the State of Guo was overrun in just a couple of days. On their way back home, the Jin troops captured the ruler of Yu and conquered his state as planned.

In captivity, the ruler of Yu regretted that he did not listen to the warning of “lips and teeth.” But it was too late.