Imagine my non-surprise to hear this tidbit on a drizzly Texas Panhandle day. It is that Defense Secretary James “Mad Dog” Mattis told associates he isn’t sure he can work with John Bolton were he to be named national security adviser to the Donald J. Trump administration.

Who knew? Yes?

You see, Mattis is a grownup. He’s a retired Marine Corps general with combat experience. He knows war. He’s seen it up close. He’s been to hell and lived to talk about it … were he so inclined.

Bolton is more of a “chicken hawk.” He doesn’t have the kind of real-world experience that Mattis has piled up. Yet he stands ready to recommend war at almost any turn. The Hill reports that White House chief of staff John Kelly, another retired Marine general, also is unhappy with Bolton’s selection as national security adviser.

Well, now the president has appointed Bolton to be the national security adviser. The decision appears to have isolated Mattis, who had a kindred spirit in the national security adviser’s chair for about a year. Army Lt. Gen. H.R. McMaster is stepping down as national security adviser and reportedly is retiring from the Army.

He and Mattis double-teamed as a reasonable tandem of advisers who were willing to advise Trump against acting rashly — even though they weren’t always able to persuade the president to follow their advice.

Gen. McMaster is now gone. Is “Mad Dog” Mattis the next grownup to be shown the door?

Chaos is king in the Trump White House.