In 611 BCE, the powerful state of Jin summoned its vassal states to a meeting, but Duke Mu of Zheng failed to appear. Duke Ling of Jin declared, "Zheng harbors disloyalty toward us," and prepared to attack.
When the state of Zheng received news of Jin's displeasure, they hastily sent a messenger to Duke Ling of Jin with a letter explaining their difficult position between the two great powers of Jin and Chu. "We fear the north, we fear the south," the letter read, "and it is only our fear of annihilation that kept us from attending your invitation." It went on to recount Zheng's long history of friendship with Jin, how despite their small size and weak position, they had never dared to slight Jin, offering regular tributes and visits with all their might. Yet Jin remained unsatisfied, suspicious, and oppressive. "If this continues," the letter warned, "Zheng will have no choice but to perish—and once destroyed, we can no longer fulfill our duties to you. As the ancients said, 'If you fear the head and fear the tail, how much of the body remains unafraid?' And also, 'A dying deer does not choose its shade.'" The letter concluded that if pushed to the brink, Zheng would have no choice but to seek refuge with Chu. Source: *Zuo Zhuan*, "Duke Wen's Seventeenth Year"
Seeing that Zheng maintained a firm stance, the state of Jin, fearing a conflict with Chu, decided to make peace with Zheng.
The idiom "fear the head, fear the tail" describes being afraid of everything, symbolizing timidity and excessive worry that prevents any real achievement.
Source: *Zuo Zhuan*, "Duke Wen's Seventeenth Year"
Meaning of the Idiom: Later, the Chinese idiom "畏首畏尾" came to describe being afraid of everything, symbolizing timidity and excessive worry that prevents any real achievement.