Defense Secretary Jim Mattis at the White House on Feb. 7. (Carolyn Kaster/AP)
Opinion writer

The country should be immensely grateful that Secretary of Defense Jim Mattis is there — not only because he is a steady hand and speed bump on President Trump’s rash decisions, but because every week he demonstrates how one can serve without degrading one’s self in this administration. He recently played a key role in protecting the country no less than four times.

First, he diffused Trump’s much-mocked parade idea — and gave young people a lesson that will serve them well. He had this exchange with reporters on Thursday:

Reporter:  You didn’t mention location when you were talking about the parade earlier.  You said the size, participants . . .

Mattis:  Oh I’m sorry.  Well as I understand, he wants a parade in Washington DC, but that’s a good question.  I’ll see what we put together for options.  Is your — is your hometown looking for it or something? (Laughter.)

Reporter:  . . . asked you to do something like this, you’re a student of history.  I mean don’t — do you have any misgivings about this?  Doesn’t this seem like the thing Russia and China . . .

Mattis:  I’m not paid for my feelings; I save those for my girlfriend.

I am not paid for my feelings. What an exquisite expression of humility and rationality.  Whether in school or in the workplace, young men and women would be smart to keep in mind that it is not all about them and their subjective emotions; it’s about the mission and objective reality. (Mattis, in this regard as in many, is the anti-Trump.)

In the same media availability he was asked about possible deportation of “dreamers” who are enlisted in the military. He showed the character and compassion we expect of someone in leadership:

“We would always stand by one of our people and I have never found Department of Homeland Security unwilling to take any call from anyone on my staff, if we in fact, found somebody who had been treated unjustly. The challenge goes back many years is what I’m told, where we’ve had some people who have been in or something and something’s happened.  But what I wanted to do first of all is make certain we don’t have any more problems from it. And in that regard, I maintain close collaboration with the Secretary and she’s been very helpful and her staff on our staff level, too, we talked about it.”

We would always stand by one of our people.  If only the commander in chief adopted that sentiment toward all hardworking, law-abiding dreamers.

Third, Mattis played a constructive role in moving Republicans (with whom he holds sway) toward a budget deal by reminding them of the necessity of properly funding the military. As the most respected Cabinet member, he was brought to the White House briefing room to make his pitch for a two-year budget:

“Failure to implement or fund the 2018 National Defense Strategy will leave us with force that could dominate the last war, yet be irrelevant to tomorrow’s security.  We need Congress to lift the defense spending caps and support a 2-year budget agreement for our military.  America can afford survival.

For too long, we have asked our military to carry on stoically with a success-at-any-cost attitude.  The fact that our volunteer military has performed so well is a credit to their dedication and professionalism.

We expect the men and women of our military to be faithful in their service, even when going in harm’s way.  We have a duty to remain faithful to them.

Absent a budget this year, America’s military will not be able to provide pay for our troops by the end of the year.  We will not be able to recruit the 15,000 Army soldiers, and 4,000 Air Force airmen required to fill critical manning shortfalls; we would not be able to maintain our ships at sea with the proper balance between operations and time for training and maintenance; we would have to ground aircraft due to a lack of maintenance and spare parts, degrading our pilot’s proficiency; we would deplete the ammunition training and manpower required to deter war; and we would delay contract for vital acquisition programs necessary to modernize our force.

I cannot overstate the negative impact to our troops and families’ morale from all this budget uncertainty.”

And finally, The Post reported:

For weeks, Mattis had been resisting requests from the White House to provide military options for Iran. Now Trump made clear that he wanted the Pentagon to deliver a range of plans that included striking Iranian ballistic missile factories or hitting Iranian speedboats that routinely harassed U.S. Navy vessels.

“Why can’t we sink them?” Trump would sometimes ask about the boats.

National security adviser H.R. McMaster and his staff laid out the president’s request for Mattis in a conference call, but the defense secretary refused, according to several U.S. officials, who spoke on the condition of anonymity to discuss sensitive internal deliberations. At that point, McMaster took Mattis off speakerphone, cleared his staff from the room and continued the conversation.

Sometimes ignoring Trump is the bravest, best course of action.

For all that, and for his constant example of integrity and honor, we can say well done, Secretary Mattis.