So, he kind of set a cat among the pigeons on Friday by coming out publicly and saying that he couldn't agree positively on these two countries' Nato membership.

他在周五公开表示，他无法就这两个国家的北约成员资格达成积极一致，因为这会闹得鸡犬不宁。

" To put the cat among the pigeons" means to do something that causes alarm or concern – to do something or say something that makes a lot of people angry or worried.

“to put the cat among the pigeons”意思是做一些引起恐慌或担忧的事情——做一些或说一些让很多人生气或担心的事情。