You should be concerned if you're China's neighbor. In addition to the ones listed above, China had a border conflict with USSR in 1969 in Far East - [0]. China

You should be concerned if you're China's neighbor. In addition to the ones listed above, China had a border conflict with USSR in 1969 in Far East - [0]. China invaded the contested Paracel islands which was under South Vietnam's control at the time - [1]. China killed 64 Vietnamese solder in the Johnson South Reef Skirmish - [2] Worst of all, China directly supported and controlled Khmer Rouge, causing the death of at least a million Cambodians, 25% of their population. The worst genocide since WW2 that seems to have been gradually forgotten - [3]. Note that most Western countries also bore the responsibility, albeit indirectly, by the virtue of looking the other way. All of that happened when China was only a regional power with a poor economy. [0] - https://en.wikipedia.org/wiki/Sino-Soviet_border_conflict https://en.wikipedia.org/wiki/Sino-Soviet_border_conflict [1] - https://en.wikipedia.org/wiki/Battle_of_the_Paracel_Islands https://en.wikipedia.org/wiki/Battle_of_the_Paracel_Islands [2] - https://en.wikipedia.org/wiki/Johnson_South_Reef_Skirmish https://en.wikipedia.org/wiki/Johnson_South_Reef_Skirmish [3] - https://en.wikipedia.org/wiki/Cambodian_genocide https://en.wikipedia.org/wiki/Cambodian_genocide