President Trump demands loyalty from everyone around him. And his method of obtaining it is often unorthodox: By forcing people to sign off on — or even vouch for — his most controversial and nonsensical ideas. The people in his orbit almost always do, to one extent or another, because the alternative is undercutting the president of the United States. Once they’ve bought in, their fate is more tied to his.

Defense Secretary Jim Mattis has to this point largely avoided such an arrangement. Speaking in public infrequently, he has earned a reputation as a bipartisan, steadying force within the administration. And with Nikki Haley’s impending exit as U.S. ambassador to the United Nations, he’s set to be the most popular and reputable Cabinet official left.

But Mattis’s tolerance is now being tested — as is his reputation.