Equation
Lieutenant General
Oh no, Vietnam is stuck with China for better or worse, but that does not mean they won't cause China any damage if they really want to, they are the only real resistance left for China in Asia Pacific now that Philippine has folded. US carrier is going to dock in Vietnam next year, and Vietnam is probably going to start to buy US weapons and with any chance another US base right on China's footstep.
Does this going to effect China in the long term? not really, does it going to have a impact on China in the short term, very much so.
It seems your argument is that its in Vietnam's DNA to hate China, and also in Vietnam's DNA to submit to Chinese dominance therefore China should not worry about Vietnam, because eventually history will win out and China will have its way... to be fair yeah that is the historical pattern of interaction of Vietnam and China. But still, in the modern age, do not underestimate a unified nation of 90+ million under China's noses and being very hostile to China, they are capable of doing real damage to Chinese interest if push come to shove. Therefore Vietnam's action towards China does matter a lot more than you like to easily dismiss, and for same reason, a unified Korean with similar sentiment towards China will be the same.
Bottom line a 90+million does NOT match with 1.3+Billion...period! I don't why you still think this little guy perspective is some how be able dictate to China and the people, when Vietnam never does it before for millennials. There are more Vietnamese women marrying to Chinese men than the other way around. I don't see them hating on China.
You forgot the time when China recently told Vietnam to stop drilling for exploration of resources in the contentious SCS and they did because they thought Trump had their backs.