出处：按学科分类—语言、文字 中国对外翻译出版公司《汉英成语词典》第225页（223字）
先动手制服对方，表示主动，例我军见敌人有暗袭的企图，于是先发制人．大举出击。
When we got wind that the enemy was planning a surprise attack，we took the initiative and struck first and thereby took them unawares．