Korea, Tibet and Vietnam all lie within China's historic sphere of influence. Korea (with the "help" of Japan) declared independence from Qing China only until the late 1800's, right up to the collapse of the Qing. Tibet was also part of Qing China. The PRC today (as did the ROC) claims itself as the modern successor state of the Great Qing Empire.
My point was that the Chinese have never fought in a campaign that did not have a historical context with itself. Nor have the Chinese engaged in war with a country that did not border it or was never claimed as Chinese territory.
With consideration of these points, one can reasonably say that the only foreseeable Chinese engagement in the near future is over Taiwan. Not over Africa, Iran or S America.
In addition, the ideology their leadership and government continues to embrace compels them to spread the socialist/marxist/communist word as far as they can. Despite whatever happy face is put on it, (and I have been on the ground there and seen it) they are still there and if anything are turning into a more fascist model which could make things even worse.
You are free to see it however you wish and I am comfortable letting others read our views, look into it and decide for themselves.