How did General Milley's Actions Prevent a War?

I guess its a reading comprehension thing huh.
So tell me which one of these you don't know about and I will educate you.
You don't know
There is a transcript of the phone call obtained by Woodward and Costa of Milleys conversation with the Chinese General
You don't know
Milley told China, "If we're going to attack, I'm going to call you ahead of time,
And you don't know
Milley isn't disputing it, but actually defending it
And you don't know
The Secretary of Defense Miller had no knowledge of it

Which of these do you need help with

 

That is one of the stranger takes on this I have seen.

Who is claiming Milley 'prevented' WW3 and why pay attention to them?

My understanding is that Milley & others in the US military/Administration were: 1) Concerned about Trump's erratic behaviour; 2) hearing that China was getting nervous about how he might behave. So, a number of people, including SecDef Esper, reached out to senior Chinese officials to ensure them that Trump's behaviour wouldn't be allowed to become a military threat.

Nervous people can make mistakes. A small incident might potentially become a serious one. Remember that one of the case studies senior officers would learn about is Able Archer 83, when Russia almost launched a first strike based on its perceptions of Ronald Reagan & a NATO command exercise. No one wants to take the risk something even a fraction that bad might happen again. So, faced with imcreased tensions multiple senior Defence figures reached out to their Chinese counterparts to ensure that nothing happend due to a misunderstanding.

I don't know how lowering tensions could be seen to elevate them.