The New York Times reports:
Back when their relationship was fresh and new, and President Trump still called his defense secretary “Mad Dog” — a nickname Jim Mattis detests — the wiry retired Marine general often took a dinner break to eat burgers with his boss in the White House residence. But the burger dinners have stopped.
In the second year of his presidency, Mr. Trump has largely tuned out his national security aides as he feels more confident as commander in chief.
Facing what is likely to be a heated re-election fight once the 2018 midterms are over, aides said Mr. Trump was pondering whether he wanted someone running the Pentagon who would be more vocally supportive than Mr. Mattis, who is vehemently protective of the American military against perceptions it could be used for political purposes.
The full article is worth your time.