As a former White House chief of staff, the best advice I could have given Gen. John F. Kelly has been overtaken by events: Don’t take the job.

Kelly, who has rendered extraordinary service and sacrifice to the nation, just signed up for what may truly be an impossible mission: bringing discipline, order and strategic focus to the chaos that is the Trump White House.

To have any chance of succeeding, he will have to accomplish three extraordinary tasks, all at odds with President Trump’s instincts.

First, discipline. There’s no doubt the decision to replace Reince Priebus with Kelly was based on the hope that a former four-star Marine general could get this menagerie in line. You don’t have to compare the Trump White House to no-drama Obama or the buttoned-down Bush operations to know there is simply no precedent in modern history for the current White House culture of factionalism, infighting and lack of respect among senior staff members. Of course, most of Trump’s team are simply modeling their behavior on that of the boss.