It's not the military's job to oppose Trump

To the extent that Mattis and Dunford disagree with the policy, they owe it to the nation and their president to give their best advice against it. Despite his impulsiveness, Trump has demonstrated that he is persuadable by Mattis in particular. Presuming they have tried and failed to convince the President to reverse course, however, they have two legitimate choices: carry out the order to the best of their ability or resign their posts in protest and continue their fight from the outside.

While I agree with those who argue the deployment is an unseemly “political stunt,” that would seem an odd hill, indeed, to choose to die on. Unless they believe the order unlawful or one that seriously endangers U.S. national security—and it would be difficult to make either argument based on what we know so far of Trump’s plan—Mattis and Dunford are much more valuable inside the room where they can help steer the policy clear of legal and moral pitfalls.