Will China Back North Korea in a War?

If it came to war, US nuclear strategy would be to initiate a massive preemptive strike on missile bases and any Command and Control - this has been the central strategy concerning Russia and China for decades, and would almost certainly be used against North Korea. Considering how small NK's arsenal is, and how quickly it would be taken out if the US ever decided to initiate, it's likely that by the time China could respond, NK would be in no position to retaliate making backing them in a war useless.

So far the conventional wisdom is that China emphatically does not want a unified, US-leaning Korea on its border. Avoiding this is worth any amount of trade. China's priority is security. Even a unified Korea without US forces present would need to be a Chinese client state to be acceptable in Beijing and that ain't likely anytime soon.

I wonder how much trade China has with North Korea vs. South Korea. Or, vs. the US. That might be the best indicator of what China will do in the event the US strikes North Korea. For all we know, China may trade more with a united Korea than with a divided Korea. I wish Trump would make that argument -- that a united Korea would be wealthier and a bigger trading partner with China than the current situation.