What did Donald Trump do today?

He gave Kim Jong-un even more control over his own political destiny.

Trump's tweet this evening about North Korea's peace overtures was less giddy than last Friday's, in which he simply declared "KOREAN WAR TO END!" But by endorsing North Korean propaganda on the subject of its nuclear tests, it essentially committed Trump to a course in which his own personal credibility is tied to Kim Jong-un's satisfaction with any peace negotiations.

For example, tonight's tweet once again referenced the promised closing of a nuclear test site. The site in question is already doubly useless to the Kim regime: it has already served its purpose of verifying that North Korea can produce a reliable hydrogen bomb, and it was probably destroyed in the process. 

It also referenced a "Failing New York Times" article with a headline that might have sounded vaguely positive for Trump--"Kim Prepared to Cede Nuclear Weapons if U.S. Pledges Not to Invade." But the body of the article pointed out that North Korea has used nuclear peace overtures to wring concessions out of its enemies several times already.

The NYT article also made clear that Kim has no obvious motivation for ever giving up his nuclear bargaining chip--a point widely agreed upon by North Korea experts. But because Trump has now put essentially all of his political capital in Kim's hands, both conservative commentators and the same New York Times he approvingly tweeted about are concerned that Trump's need for a political win will give Kim leverage he never would have had otherwise.

It's unclear whether Trump knows these things and is knowingly putting himself in this position, or whether he simply doesn't understand that Kim--or "Little Rocket Man" as Trump called him not long ago--isn't as trustworthy as North Korean propaganda makes him sound.

Why is this a problem?

• Even the tiniest hint that a president's personal motives can be separated from those of the country he represents is horrible.

• It's stupid to give a nuclear-armed enemy nation control over the narrative.

• It's beyond incompetent to commit so enthusiastically to a particular outcome in international diplomacy in advance.

• It shouldn't be this easy to manipulate a child, much less the President of the United States.