We need to let China know that the issue needs to be resolved now to avoid war. We should start with voluntary evacuations of old people and young children from Seoul and, if the situation does not get resolved, mandatory evacuations of all non-workers, followed by a plan of immediate evacuation of everyone else if needed. THAT would get peoples' attention in Beijing (along with the movement of a few extra carriers and putting all US troops in Japan on high alert).

We then let China know that we find three options acceptable:

(a) the regime signs a peace treaty, dismantle its nuclear stockpile and finds some way of reforming itself

(b) China takes over direct control of North Korea and helps to reform its economy, with any Chinese troops leaving at the same time as US troops leave South Korea to permit the North to be absorbed by the South

OR

(c) we impose a complete blockade on North Korea and let the regime collapse on its own or, if need be, we destroy the regime militarily