China will have no reason to attack their best customer. It would serve no purpose. On the other hand, wealthy Chinese citizens will want and demand land, so China will have to find way to obtain land. I believe they will do that in two ways. The first will be by emigration and de facto colonization. That is already occurring. The second way will be by assimilation of neighboring countries. My guess is that North Korea is very high on that list. It wouldn't surprise me to see North Korea become a client state of China within 15 years. I doubt the new ruler in North Korea will be able to hold it all together there after daddy dies.