This is less true than naive abalysis suggests, because relative deprivation is a significant source of disutility and trade that is “mutually beneficial” before the effects of relative deprivation are considered is often so unequal inn benefit distribution that the total net utility on one side is negative.
Classical comparative advantage arguments for trade tend to ignore the disutility from relative deprivation.
That's one of many places where it occurs, yes (it also happens locally.) Trade can exacerbate it, because even superficially mutually beneficial trade doesn't advance the wealth on both sides equally, and the degree of difference in material position, not merely it's binary existence or not, is a key factor in the magnitude of the resulting disutility.
I suppose this is a matter of judgement though and not an objective fact so to each their own.
That's a nice strawman you've set up, but no one in the discussion actually claimed that.
China (and India) have all the right and incentives to protect their continents from bad economic influences.