NK invading SK would be roundly crushed in an afternoon by the carrier group posted there SPECIFICALLY to prevent that from happening, not to mention SK forces themselves.

I would like to see which military war game has ever shown that. I have never seen that at all. Can you please show the citation for that since it contradicts everything I have ever read on the topic.

aiwan is in the middle of building up their forces again, we have forces in the region ready and able to assist (posted there, again, specifically to deter Chinese aggression), and we have ally forces across southeast Asia, including Vietnam, New Zealand, and Australia, who are willing and able to come help if needed.

We do not have a force large enough to fight China in the region while we are tied up in Ukraine. Vietnam is not going to war with China. New Zealand and Australia do not have a capable enough force to add much value. That is why they are asking the United States to build bases.