As Vice President Pence fawningly praised President Trump’s achievements at a Cabinet meeting Wednesday, the camera caught Defense Secretary Jim Mattis shuffling his papers, adjusting his water glass and fidgeting in his seat until the adulatory speech ended.

As this year winds down, Mattis remains the good soldier, seated at Trump’s left and guarding his flank, trying to avoid the political fracas of this presidency. He’s the rare Trump appointee who doesn’t seem to have been damaged by his proximity to power. His Pentagon is a force for stability at a time when so many other American institutions are stressed.

Mattis’s only problem may be this bipartisan popularity: He’s the Trump official who’s admired by people who don’t like Trump. That rubs some Trump enthusiasts the wrong way. Former White House adviser Stephen K. Bannon is said to view Mattis as too close to the traditional foreign policy establishment. But Trump himself seems respectful of the retired Marine general he likes to call “Mad Dog.”

The chivalrous Mattis is an unlikely partner for Trump. He’s a Stoic, with an almost superstitious dislike for the spotlight. It’s notable that he has avoided gloating this year about victory over the Islamic State, recalling Gen. Ulysses S. Grant’s refusal to visit Richmond after its collapse to the Union Army in 1865. Mattis clearly abhors the political parlor games that are part of Trump’s Washington.