By then, the Red Guards were nearly a spent force, and the army had to intervene to save the nation by manning civilian posts. （美國《時代周刊》）

a spent force 翻譯為“強弩之末”合適嗎？

My comments:

Spent is the past tense and past participle of spend, as in spending money on something.

And if you are a rich person but somehow spend all your money, your money is all spent, meaning all used up.

In that case, you’re no longer wealthy.

Likewise, if you spend all your energy, then all your energy is spent and you’re left exhausted and powerless.

And so, therefore, if you’re a spent force, then you’re not as forceful as before because all of that force you had before is gone.

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Go to Zhang Xin's column

本文僅代表作者本人觀點，與本網立場無關。歡迎大家討論學術問題，尊重他人，禁止人身攻擊和發布一切違反國家現行法律法規的內容。

About the author:

Zhang Xin（張欣） has been with China Daily since 1988, when he graduated from Beijing Foreign Studies University. Write him at: zhangxin@chinadaily.com.cn, or raise a question for potential use in a future column.