Exactly. That train trip is the key factor here everyone is forgetting. The whole scenario was causing Japan and SK to invite too much US hardware so close to China and was looking more and more like an excuse for pre-emption. China isn't fully ready for a face off.

Came here to say this. For the first time, in the last 6 months China properly put the economic screws on North Korea. They shut down the border markets and routes and also banned North Korean sales of coal, seafood and textiles. They have made token gestures after previous nuclear tests and such, but this was real, consequential action. Also Kim recently returned from a rare train trip to Beijing. If you want to understand what's going on, follow the money. Yes North Korea has improved a bit economically in the last 5 years or so, but China has finally made it crystal clear to Kim that the show is over.