What did Donald Trump do today?

He adopted the language of North Korean propaganda to talk about US military exercises--and then canceled them without warning his own Defense Department or allies.

For all the enormous pageantry surrounding the Trump-Kim meeting, there was virtually nothing concrete in the statement they signed today. North Korea committed to precisely nothing it had not already agreed to, except for a promise to "work towards" an agreement on "denuclearization." (North Korea interprets that phrase to mean something involving keeping its current arsenal.)

What Trump gave away, however, is a little more substantial--and it appears to have been a spur-of-the-moment decision. Trump promised to immediately end what he called "war games," otherwise known outside of North Korean propaganda as joint military exercises between the United States and South Korean armed forces. Again using language identical to DPRK state media, Trump said the exercises were "provocative."

This is valuable to North Korea not merely because it might degrade its enemies' performance in the event of a conflict, but because it represents a move towards decoupling the U.S./South Korean military relationship. While Kim has been evasive about "denuclearization," he has been adamant that a condition for a lasting peace would be a withdrawal of the American military presence from the region.

Kim's ability to extract this promise from Trump was so significant that the North Korean delegation immediately reported it to the Chinese government, which would also benefit from a US withdrawal. China then announced it before Trump did. This meant that China knew about Trump's promise of a military disengagement before either South Korea or Trump's own Department of Defense did.

This sort of result was exactly what diplomats and North Korea experts feared would come out of a meeting between Trump and Kim but none of their aides and advisors--especially after Trump insisted that his ability to get the "feel" of things made preparation irrelevant.

Late this evening, North Korean state-run media began announcing that Trump had agreed to cancel sanctions against the Kim regime. The White House has not yet commented, and there is no way to know for sure that this is not actually true.

Why does this matter?

• A president who can't be bothered to prepare for something like this is derelict in his duty and unfit for the office.

• It should not be possible to so easily manipulate the President of the United States during a 45-minute meeting that he comes out quoting his enemy's propaganda.

• Making decisions that affect our allies without consulting them is a very bad idea.

• Making military decisions without consulting our military is an insanely bad idea.

• Deals in which you get nothing for something are not usually good deals.