If I was just complaining about border skirmishes, then I'd mention India or something. The attack on Vietnam was more than just a "minor border skirmish".
Well, feel free to explain how the attack on Vietnam constitutes an occupation. Are you suggesting China's military action was carried out with the intent of annexing a part of Vietnam?
I'd more say that the military occupation was done for the sake of confrontation (this is similar to the official Chinese line). It was a really senseless invasion, as far as I can tell (and I disagree with the Vietnamese line that the war was expansionist).