Speaking of North Korea China continues having a hard time convincing the North Korean leadership that ignoring serious economic and corruption problems is not acceptable. Many Chinese, especially those living near the North Korean border, find little in North Korea that makes sense. For example China completed a new bridge across the Yalu River in late 2014, providing another route for trade between China and North Korea. But the bridge is not open yet because North Korea has not completed the roadwork on their side of the river. No reason is given by North Korea, it’s just the way things are there. Many Koreans (north and south) believe China is fed up with the incompetence and intransigence of the North Korean leadership and is now willing to wait for the North Korean government to collapse and then go in and rearrange the situation to its satisfaction. At the same time many North Korean leaders blame their problems on China.
The bridge situation is interesting. I'm sure that reflects "the way things are there," but there is another reason for why North Korea hasn't built the road on their side that is more practical, I think.
Note the part about expecting China to "go in and rearrange the situation to its satisfaction." That means invading North Korea.
And that bridge? That feeds into a North Korean road network being improved. Which would be part of the invasion route from the north:
So if there is a dispute among the powers about who should administer a collapsed North Korean state, China is making sure that the main highway into North Korea allows the Chinese army to rapidly drive south to Pyongyang.
And from there, the Chinese army can fan out to other parts of North Korea to various provincial capitals.
Despite the DMZ in the south that will hinder movement north, South Korea might make a race of it if there is real collapse despite the deployment of the vast majority of North Korean troops in the south.