[pc86]

Even the question assumes that because the answer is "a few billion people die" it's not possible, and because of that (false) assumption, the first thing isn't possible.

If China starts sinking US ships half the people reading this thread will die before ever hearing about it. That doesn't mean China would never sink a US ship.

[Spooky23]

We remain alive today after decades of nuclear brinksmanship, because in general, people don’t want to die.

The longer term strategic outlook for the US is… not great. Why would China poke the bear when the bear has teeth? Wait for America’s internal instability to escalate, then roll into Taipei without a shot fired.