The reason John Kelly and White House communications officials insisted late last week that McMaster wasn't going anywhere for now — despite a WaPo story saying he was done — was because the president told them to say that. And they genuinely thought he’d take some time to ease McMaster out.
What I'm hearing: An administration source told me that the aides thought Trump probably believed that in the moment..."He’s impulsive. He makes snap decisions but they're weird snap decisions ... He publicly ruminates for six months and then says: 'I have to do this right now.'"