“China has no fear of a united Korea.”
...as long as it is their unified Korea - a communist dictatorship and Chinese vassal.
A pro-US unified Korea with domestic political freedom would be a terrible example that could inspire their own population to get all uppity, and aspire to freedom themselves.
Also, North and South Korea have the fourth and fifth biggest Armies on Earth - a non-trivial force sharing a long border with them.
China has had an aggressive program of trying to lock up natural resource supplies - it relies on North Korean supplies of several mined commodities, like iron tungsten and coal. North Korea also has large deposits of rare earth metals, for which the Chinese went to great lengths to lock up the market.
Also, China has made a lot of diplomatic hay doing a Good Cop/Bad Cop routine, with North Korea playing the crazy attack dog for them. They would hate to lose that leverage.
If the files got out about what China actually did and does in North Korea (like proliferating nukes to and through N. Korea), they would be liable for sweeping sanctions.
North Korea is Communist China’s single closest and most reliable ally - arguably its only such ally in the world.
From the video they appear to be DT-30s, tracked re-supply vehicles.
http://www.army-technology.com/projects/dt-30-vityaz-articulated-tracked-vehicle/
They are for use when rail and roads are unusable.
Imo the Russians appear intent on re-supply NK in the event of an attack.
The whole ‘refugee-thing’ is nothing but an ignorant delusion of myopic Westerners.
With “allies” like this who needs enemies?
China will eventually fall like the Soviet Union and become an ordinary Welfare State. But it is in their interest to get rid of the lunatic.
And it is clear which model of development is in the interest of China. By the time Korea becomes truly unified China may not even be Communist. That process is not going to be painless or osmosis-like by any means irrespective of the costs of a war to force it.