“I had no intent to enter the political fray or address policy,” Dunford told us in an email. “Alex Vindman was one of my officers and it was an easy decision for me to speak about him after political figures and members of the media questioned his loyalty to the Constitution and our Nation.”

Read: The man who couldn’t take it anymore

Former Secretary of Defense James Mattis is perhaps the highest-profile example of the silent general, and he has repeatedly declined to discuss policy or the president he served. “If you leave an administration, you owe some silence,” he told The Atlantic’s editor in chief, Jeffrey Goldberg, recently. Mattis has said he won’t criticize a sitting president, but he seems comfortable doing so once a president has left office. In his new book, Mattis freely criticizes both George W. Bush and Barack Obama. Yet his resignation letter to Donald Trump can be read as an implicit criticism of the president, in that he laid out his belief in the importance of alliances and declared that Trump needed a defense secretary whose views better aligned with his own.

Following one of Trump’s most controversial defense-policy decisions yet—the announcement that he would take U.S. troops out of the way of a Turkish assault on America’s Kurdish partners against the Islamic State—we made efforts to contact more than two dozen four-star generals and admirals who retired under Trump to see whether they believed the moment warranted breaking silence.

But Dunford was one of only three we reached who would comment for this story on the record. (Some former senior officers have been willing to criticize the president or his policies anonymously, however.) We found that, for now, the military’s apolitical ethos is stronger than some commentators have argued it should be; and in any case, Trump tends to have more support among veterans than the general public, though nearly half say he doesn’t listen enough to military advice, according to one poll. But there are notable exceptions.

Read: Top military officers unload on Trump

John Kelly, the retired four-star general who served for a time as Trump’s chief of staff, recently made the eye-popping admission that he had warned Trump he would be impeached if someone wasn’t there to check his instincts. Prior to that, Joseph Votel, the recently retired head of the U.S. military’s Central Command, wrote with Elizabeth Dent in this magazine that “the abrupt policy decision to seemingly abandon our Kurdish partners could not come at a worse time.”

Retired four-star generals have come up with a variety of ways to express doubts about the president. Their methods range from the passive-aggressive (like former Chairman of the Joint Chiefs Martin Dempsey’s series of #leadership tweets drawing implicit contrasts with the president’s conduct), to the explicit (like the Osama bin Laden–raid architect William H. McRaven’s op-ed declaring that if the president won’t demonstrate the leadership America needs, “it is time for a new person in the Oval Office … the sooner, the better,” or ex–CIA Director Michael Hayden’s outright call for impeachment). They also favor the kind-of-but-maybe-not-really joking about Trump’s own lack of military service due to bone spurs (like Mattis’s remark in October that “I earned my spurs on the battlefield … and Donald Trump earned his in a letter from a doctor”).