weak link
noun [ C usually singular ] uk/ˌwiːk ˈlɪŋk/ us/ˌwiːk ˈlɪŋk/
薄弱的环节
a weak part, especially the weakest part of something
They're a fairly good team - their only weak link is a relatively inexperienced goalkeeper. 他们是一支相当强的球队——唯一的薄弱环节就是守门员相对来说经验不足。
A chain can only be as strong as its weakest link, so we must look at the least committed country to see if the alliance will hold. 一条链子的强度取决于它最薄弱的环节。所以必须观察最不坚定的成员国来确定联盟是否牢固。