Tuesday on CNN International’s “Amanpour,” host Christiane Amanpour asked former Secretary of Defense James Mattis why he did not resign over President Donald Trump’s “rhetoric.”

Amanpour said, “There are many many things that President Trump said and did over the years that potentially rose to the level of unacceptability in the public sphere. There were many many reasons potentially for somebody, such as yourself, to resign. Why not over any of these?”

She played clips of the president’s remarks after the Charlottesville violence, from Helsinki with the President of Russia Vladimir Putin and saying he and Kim Jong Un “fell in love.”

Mattis said, “If you go into the military, you swear an oath to uphold the constitution. The elected commander-in-chief is the elected commander-in-chief, but if we’re going to protect this democracy, even in its most raucous moments, even when there are fundamental issues going on, you don’t want the Defense Department coming in and saying we’re not going to defend the country today.”

He continued, “The thousands of young troops — they do not get a chance to say ‘I’m going to quit today.’ So what you do is you protect the institution, you protect the country, you stand up for the constitution, but what you don’t do is get engaged in the political fray, the day-by-day, especially right now when it’s so corrosive, you don’t get involved in that and wonder why the country’s now vulnerable because you’ve allowed the troops to be distracted.”

He added, “Abraham Lincoln in 1865, early 1865, the war is still going on, the country is tired of it, there’s just been an election. I don’t think the votes are even all counted yet because it takes months to get the full count. He sends a one-sentence letter, telegram actually to General Ulysses Grant. I’m paraphrasing here. Let nothing that has happened in the political realm disrupt, delay your military operations. In other words, keep your head focused on defending the country. I’ll take care of the politics. That is the tradition from Abraham Lincoln to now that the U.S. military stands by. And by the way, all those young men and women who raise their right hand, all volunteers in a rally to the flag and give you and I and all the rest of us here a blank check payable with their own lives to uphold the Constitution. They’re the people you stay focused on when you’re dealing with the defense of the country. I’ve spent 45 years in uniform or as a secretary of defense. And that’s where I stand.”

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