“South Korea has now ordered the evacuation of the islands near the border with the North.”Evacuating the islands is an uncertain indicator. It could be a sign of a capitulation or it could be evidence of an imminent escalation of the conflict. If South Korea was anticipating further combat operations the first thing to do would be to evacuate civilians. We need to look for evidence that air defense systems and counterbattery are on a higher state of alert or that measures are being taken to protect the civilian population of Seoul. While that may not be likely in any given case it is possible and will have to happen eventually.
If high level consultations, leading to real military coordination, happen among Australia, India, The Philippines, Vietnam, Taiwan, Japan and South Korea then that would be the signal to the Chinese that the DPRK has gone to far. Given the antipathy between Korea and Japan the Chinese know that they have a lot of room to work with before their victims will cooperate to contain them. Once that barrier is broken, and the withdrawal of the United States may force its former clients to cooperate, the ability of China to isolate and bully, whether directly or by proxy, will decline dramatically.