China sells to North Korea. I doubt they would like to lose a communist ally. China is just as totalitarian as they are-don’t doubt it. Would they sit idly by and allow their natural ally next door to be invaded by the US?? Wouldn’t count on it... We made that mistake in ‘50.
As said..China rides a tightrope and we know Beijing will only help rein in Fat Boy when its own extreme self-interests are threatened. Hit China's banking industry and you'll see some cooperation pretty quickly!
They know the US has no intentions of invading NKorea...there's nothing there. China is the only one has benefited by using them as a buffer zone, ..but China's investments etc. world wide now has changed that equation...cut China's banking/financial institutes would hurt China and they know it....soooo...we shall see.