We will defend our nation, even if the cost is war between China and US.
Long Live China!
I'm not going to talk about the South China Sea thing - I haven't been following that closely enough to know what I'm talking about, but war between two superpowers means the world would end within a few minutes.
Superpowers haven't fought each other since World War 2 because of the realization that within a few minutes, nuclear missiles would rain down across the entire planet and destroy everything.
Even if somehow one country managed to destroy the other country before they launched any nuclear missiles, the fallout would still drift across the ocean and would kill everyone in the surviving country within a few months.