Today's N Korea's bomb was a huge event. Blast was from a 1 mega ton Hydrogen Bomb. And N Korea claims it has miniaturized it enough to fit it on an ICBM.
Previously China drew a fine line with N Korea to not explode any nuclear bomb. Now that N Korea has crossed it, is there anything China can do besides declaring more sanctions?
A few days earlier Russia ordered its citizens to move away from N Korean border. And US-S Korea has conducted joined training and bombing strikes near N Korean border.
It's unlikely that things will escalate to full blown war overnight. But things are escalating, slowly.