Plus you are talking about events that occurred before the 'New China' emerged in the 1980's.
By 1987 China had stationed nine armies (approximately 400,000 troops) in the Sino-Vietnamese border region, including one along the coast. It had also increased its landing craft fleet and was periodically staging amphibious landing exercises off Hainan Island, across from Vietnam, thereby demonstrating that a future attack might come from the sea.
Low-level conflict continued along the Sino-Vietnamese border as each side conducted artillery shelling and probed to gain high spots in the mountainous border terrain. Border incidents increased in intensity during the rainy season, when Beijing attempted to ease Vietnamese pressure against Cambodian resistance fighters.
Since the early 1980s, China pursued what some observers described as a semi-secret campaign against Vietnam that was more than a series of border incidents and less than a limited small-scale war. The Vietnamese called it a "multifaceted war of sabotage." Hanoi officials have described the assaults as comprising steady harassment by artillery fire, intrusions on land by infantry patrols, naval intrusions, and mine planting both at sea and in the riverways. Chinese clandestine activity (the "sabotage" aspect) for the most part was directed against the ethnic minorities of the border region. According to the Hanoi press, teams of Chinese agents systematically sabotaged mountain agricultural production centers as well as lowland port, transportation, and communication facilities. Psychological warfare operations were an integral part of the campaign, as was what the Vietnamese called "economic warfare"--encouragement of Vietnamese villagers along the border to engage in smuggling, currency speculation, and hoarding of goods in short supply.
C'mon Rhonald they were not Wars.
Yes they are not as direct in your face as the USA but what they have been doing, you could call a stealth war. Which ever nation is the current super power of the world, through out history has usually used direct blunt means. Rome did it, the English Empire did it, and the USA is doing it. Sometime Willy I think you do not see that any world power, emerging or established, have thorns hidden below the rose buds.
I agree with you that they have become more open, and hopefully all nations will learn that with technology where it is today, that muscle flexing should only be done at the beach, or at the Olympics.