"If you leave an administration, you owe some silence," said former Secretary of Defense James Mattis. | Win McNamee/Getty Images white house Mattis says he owes Trump silence, but won't keep quiet 'forever'

Former Secretary of Defense Jim Mattis said in an interview he feels duty-bound to keep quiet his opinions about President Donald Trump’s leadership but that his obligation to refrain from criticism of the commander in chief is “not eternal.”

The retired Marine general, who exited the administration in December, invoked “the French concept of devoir de réserve” in a conversation with The Atlantic’s Jeffrey Goldberg for a story published Thursday.


“The duty of silence," Mattis said. "If you leave an administration, you owe some silence.

“When you leave an administration over clear policy differences, you need to give the people who are still there as much opportunity as possible to defend the country,” he continued, later adding, “We have to give the people who are protecting us some time to carry out their duties without me adding my criticism to the cacophony that is right now so poisonous.”

Pressed on whether he bears a responsibility to warn Americans about a potentially unfit president, Mattis insisted it is inappropriate to “endanger the country by attacking the elected commander in chief.”

But Mattis also indicated he might soon more vocally challenge the president and speak out about his time leading the Defense Department. “There is a period in which I owe my silence. It’s not eternal. It’s not going to be forever,” he said.

Mattis denounced a May tweet in which Trump claimed he was not bothered by North Korea’s tests of short-range ballistic missiles and promoted an insult that leader Kim Jong Un leveled against former Vice President Joe Biden.

“North Korea fired off some small weapons, which disturbed some of my people, and others, but not me,” Trump tweeted. “I have confidence that Chairman Kim will keep his promise to me, & also smiled when he called Swampman Joe Biden a low IQ individual, & worse. Perhaps that’s sending me a signal?”

Responding to the post, Mattis remarked: “Any Marine general or any other senior servant of the people of the United States would find that, to use a mild euphemism, counterproductive and beneath the dignity of the presidency.”

Mattis’ support for longstanding global partnerships and harsh words for foreign strongmen markedly diverged from Trump’s foreign policy posture, though his decision to step down from the president’s Cabinet late last year resulted from his disagreement with the president’s order to withdraw U.S. forces from Syria.

Mattis' resignation letter, which stressed the importance of the United States’ international alliances, was widely perceived as a thinly veiled rebuke to Trump’s brand of diplomacy.

“My views on treating allies with respect and also being clear-eyed about both malign actors and strategic competitors are strongly held and informed by over four decades of immersion in these issues,” Mattis wrote at the time.

Mattis’ comments to The Atlantic marked the second time this week the former Pentagon chief has hinted at the broader policy disputes with Trump that precipitated his exit from government service.

In an essay adapted from his forthcoming book and published Wednesday by The Wall Street Journal, Mattis cautioned against the “internal divisiveness” and “tribalism” overtaking American politics.

“Unlike in the past, where we were unified and drew in allies, currently our own commons seems to be breaking apart,” Mattis wrote.