I'm not sure that's true. The US can't defend an entire Pacific front, obviously, and has a shortage of ships, many of which will be busy doing other things.
Anyway, I was thinking of missiles, which China has many of, and which can reach the US (including from submarines and other ships that can maneuver closer to the US).
There is close to zero escalation room between Chinese missile strikes on the US mainland and nuclear war. If we detect incoming missiles from China there’s a good chance the US assumes nuclear warheads and makes a retaliatory strike.
That’s a real risk, but because neither side of a conflict wants to actually escalate to a nuclear exchange, it is not very likely that China will launch missiles at the mainland US. (Likewise I think the US is unlikely to strike mainland China.)
Conversely, whichever side maintains naval superiority in the western Pacific Ocean can cut off any supply chains to and from Taiwan, South Korea, Japan, and mainland China itself, without the risk of nuclear escalation. And as I stated, this is the entire issue. If you control the seas of East Asia, you basically control the world.
Anyway, I was thinking of missiles, which China has many of, and which can reach the US (including from submarines and other ships that can maneuver closer to the US).