Vietnam beat China in their last war. They hate each other. Duterte is a communist who likes China.
RE: Vietnam beat China in their last war.
How did that happen again?
“Vietnam beat China in their last war.”
Probably would not happen if there were to be a re-run. OTOH, the Chinese might opt for a limited border incursion that would allow the Vietnamese to ‘claim’ victory after the Chinese packed up & went home. And that is pretty much what happened last time.