the tail wagging the dog
小事烦扰大事
口语·批评主次颠倒
英文释义
when a small or secondary part of something dominates or controls the whole
例句
Letting one intern decide the policy is the tail wagging the dog.
典故来源
源自19世纪比喻，尾巴摇狗指次要部分控制整体。