Talks with North Korea are often cast as a tango of two: a dangerous dance between President Trump and North Korean dictator Kim Jong Un. But there is always a third character here, looming in the background. It’s China, which makes this whole situation much more dangerous for the Trump administration.

That dynamic was on display on Monday as Trump had talked up the prospect of a second summit between himself and Kim the day before, fueling speculation of possible locations. For Trump, a deal with North Korea emerged as a signature foreign policy goal that, along with his trade deals, could give him a real boost in support in the lead up to 2020. More important than that political maneuvering is the real threat posed, explicitly against the U.S. and our allies, by a nuclear North Korea that Trump is trying to mitigate.