On his first day as White House chief of staff, John Kelly has fired Anthony Scaramucci. The communications director was in office for barely a week.

We can take two things from this. First, that John Kelly is now the unquestioned chief. As I noted on Friday, Kelly's ability to succeed was dependent on his grant of authority from the president. Well, clearly that grant has been given.

Second, in this first decisive act, Kelly is illustrating the key tenets of a Marine infantry officer (his former career). The Marine officer's guidebook explains, "While there is no ideal list of attributes that guarantee success as an infantry officer some helpful attributes are the ability to lead and motivate others, willingness to accept a challenge and face danger, willingness to accept responsibility, and an interest in land battle history and strategy."

"An interest in land battle history and strategy" might be irrelevant here, but in firing Scaramucci, Kelly has shown "the ability to challenge and face danger" (via upsetting Trump, who just appointed Scaramucci), and "the ability to lead and motivate others."

Kelly clearly felt that Scaramucci had to go if the president was to get his house in order. Put simply, Scaramucci's rant last week against various senior White House staffers made his position untenable. He had irrevocably isolated himself from the team.

As his commander, Kelly had to take decisive action.

As I say, on his very first day, Kelly has shown he is in command and has the ability to command.