True, CN is just like Nazi or Jap in WW2, or Soviet, they can't survive against US due to their "living space" are not good enough as Hitler said. The only chance for CN to defeat or at least survive is taking control of 80% trade route in Asia, specially in SCS(east VN sea or West Philippines sea).
Its a big mistake if ppl keep thinking war will not happen in SCS(east VN sea or West Philippines sea) Except CN wanna have the same fate with Nazi or Jap in WW2, or Soviet,
It's very lazy to simplify the current situation with history, the real world is more complicated. Even China and USA don't trust each other, but the dependency between two are still complicated.
It's not cold war time, two nations are deeply integrated into globalization, that's the benefit for big nation with big market like China. We don't need war, we just need strong army to prevent it.
But the current world is not good for mid size nation, like Vietman.
Vietnam's surviving during 50s-70s was not by its own, it's backed by USSR and China.
Without this see how sentimental Viet was, during 80s-90's, China, US had bad relationship with it, USSR collapsed, Vitenam suddenly became the poorest nation in ASEAN.
The recent booming of Vietnam was partly because your CP tried to show friendly to China and USA, you get supply chain from China, and sell assemblied products to US and EU. Can you imagine how will you survive if China cut supply chain, or US stop importing your products with you?
Actually, China is happy to see Vietnam's progress, because a rich ASEAN will be good for RCEP and Chinese economy. Two nations have conflict on CSC, but it's still managable.
If we really want Vietnam goes down, we just raise some border conflict on land, all the forgein invesment will escape, but we don't have benefit to that.