President Trump and North Korean leader Kim Jong Un in Hanoi last month. (Saul Loeb/AFP/Getty Images)
Opinion writer

President Trump’s inexplicable moves in contravention of advice and of the United States’ national security interests usually involve Russia. Last week, however, North Korea was the hostile country on the receiving end of a gift from Trump, one that undermined his supposed policy of pressuring North Korea to denuclearize.

The New York Times reported, “President Trump undercut his own Treasury Department on Friday with a sudden announcement that he had rolled back newly imposed North Korea sanctions, appearing to overrule national security experts as a favor to Kim Jong-un, the North Korean leader.” Even for the president who governs by Twitter, this was extraordinary. “It created confusion at the highest levels of the federal government," the Times reported, "just as the president’s aides were seeking to pressure North Korea into returning to negotiations over dismantling its nuclear weapons program.”

Did Trump secretly promise this to Kim at the Hanoi summit or was this a spur-of-the-moment gambit to take attention away from the completion of the special counsel probe into Russia? Speaking of which, perhaps Russia or China implored Trump to take this action, praising his golf game or inviting him for a red-carpet visit. We don’t know because one cannot logically decipher the conduct of an entirely irrational commander in chief.

You wonder at some point whether Secretary of State Mike Pompeo and national security adviser John Bolton will finally decide to quit, or whether their willingness to be humiliated is limitless. Even Trump’s usual allies aren’t trying to explain the inexplicable.

On “Meet the Press,” there was this exchange with Sen. Marco Rubio (R-Fla.):

CHUCK TODD: The president putting out this tweet, “It was announced today by the U.S. Treasury that additional large-scale sanctions would be added to those already existing sanctions on North Korea. I have today ordered the withdrawal of those additional sanctions.” When asked for an explanation from the White House, Press Secretary Sarah Sanders simply said, “President Trump likes Chairman Kim and he doesn’t think these sanctions will be necessary.” It was a 24-hour rebuke. What does this incident do for the reliability of the United States on sanctions regimes overall?

SEN. MARCO RUBIO: Well, I’ve never seen that before from this or any administration, so something happened here. Those things have to usually be approved. In fact, I know that they are. They go through a long inter-agency process, signed off on by the president. So, something happened between the time it was announced and the time that the president put out that statement. I don’t know the answer, to be honest. I don’t know why he would do that or why it happened the way it did. It’s unusual. It’s never happened before.

CHUCK TODD: Does it — does it at all introduce any concern that — will he be there — you know, look, you have talked him into doing more in Venezuela than I think a lot of people expected. Do you trust him now on Venezuela, considering what he just did with North Korea?

SEN. MARCO RUBIO: Yeah, it’s a little different obviously. I mean, the president is, has been involved in now two one-on-one negotiations with North Korea. … So, I’m not skeptical [about negotiations] because I want it to fail; I’m skeptical because I believe it will fail. Now why — how this happened, look, you have to ask the White House. I don’t know how they issued this and then suddenly he changed his mind. I don’t know the rationale behind it. Maybe it was a good reason. But it certainly is not the way it’s normally done.

CHUCK TODD: But obviously the concern among some national security folks is, “What does this mean? We’re trying to get more of the world to align on sanctions when it comes to Venezuela and Maduro.”

SEN. MARCO RUBIO: Yeah. So, on this part, at least with North Korea, it’s not helpful, right, to have the Treasury Department go out and do something that’s been vetted and discussed. … It doesn’t make a lot of sense that that happened that way. And frankly, look, I think people around the world would look at it and say from now on, when they hear about sanctions, they’re going to want to know if — they’re going to ask for double confirmation from the White House, you know. So, look, I wish it hadn’t happened that way, and it shouldn’t have happened that way.

The House Intelligence and Foreign Affairs committees need to call for hearings immediately and figure out what is going on. (It would be helpful if Rubio could rouse Senate Foreign Relations Committee Chairman James E. Risch of Idaho to do the same, but don’t hold your breath. Risch is no Bob Corker.)

Trump came into office promising to start “winning.” All he has done since entering office is encourage our enemies and demonstrate the United States is not reliable. When he threatens an ally, he might mean it — until its leader lathers on praise. When he threatens a foe, he might mean it — until he decides his personal relationship (with a vicious dictator such as Kim!) is so good, he can “trust” our enemy.

If Vladimir Putin had Trump on the Kremlin payroll, he’d have to give him a bonus for all that Trump has done to unravel America’s alliances, convince foes we have no staying power, make hash out of “policy” to check aggressors (which is nothing more than a series of Trumpian impulses), undermine our moral authority and tear down international institutions and norms that have to date generally worked in our favor.

Trump also is prone to subvert America’s national security needs to his inane domestic gambits meant to mollify his base. He is ready to undermine U.S. military by snatching funds from military construction for his useless wall. In a recently revealed memo, Marine Commandant Robert Neller says deploying troops on the border (part of Trump’s caravan stunt) poses an “unacceptable risk to Marine Corps combat readiness." (The Military Times reports, “Without relief, the Corps would be forced to cancel a number of key exercises in Twentynine Palms, Alaska and Scotland, Neller warned, which would further degrade readiness.”

Trump is a menace to our national security. Democrats seeking to replace him should make that high on the list of reasons to boot him out in 2020.

Read more:

Jennifer Rubin: Trump’s utterly unsurprising diplomatic debacle

The Post’s View: The Hanoi summit failure exposes Trump’s weak diplomacy

Jennifer Rubin: Trump’s alarming gullibility on North Korea

Henry Olsen: No, the North Korea summit was not a loss for Trump

The Post’s View: Going big on North Korea failed. Trump should go small.