A common danger causes common action.是什么意思？

A common danger causes common action.

同仇敌忾。

common

adj. 普通的，通俗的，[数学]公共的，共有的；n. [法律]（对土地、水域的）共有权，公共用地，普通，平民；

例句
The pharmacist can assist you with the treatment of common ailments.
药剂师能帮你治疗一般的病痛。

danger

n. 危险，危险物，威胁；

例句
Many schools were in danger of closing because the children were bused out to other neighborhoods.
很多学校面临倒闭的危险，因为学生被校车送到其他社区就读了。

causes

n. 原因( cause的名词复数 )，动机，（某种行为、感情等的）理由，缘故；

例句
Allergy to cats is one of the commonest causes of asthma.
对猫类过敏是哮喘病发作最常见的诱因之一。

action

n. 行动，活动，功能，作用，手段，[法]诉

例句
The government is taking emergency action to deal with a housing crisis...
政府正采取紧急措施解决住房危机。