Greetings to all friends and teachers here:
Yesterday i came across this idiom " deal breaker" when i was reading the VOA News article. I donot really understand the meaning of it, so i'd like to ask for help in what does it mean and how to use it correctly in my own writting and speach. Thanks in advance!
The sentence in the original article goes like this: " After agreeing in principle last month to dismantle its nuclear weapons programs, Pyongyang turned around and insisted the international community provide it with a light-water nuclear reactor first. The other parties to the talks have rejected this. Mr. Richardson said the North Koreans expressed some flexibility on the issue, and said he does not believe it is a deal breaker."
Does " deal breaker" mean the starting point in making a deal or deas it mean the most significant point in a deal? please explain a bit.