The Pacific ocean is a hell of a barrier. A fleet would never make it. Invading with air power only would be a bad joke.
Humor me for a moment. If China loaded cargo ships, planes and all means of transportation with hundreds of thousands of regular(non military) people and set sail for the US how would they be stopped? Sink ships carrying 25,000 people? Down the airplanes? As I mentioned in my op I think China could walk in fairly easily and take over. America and the rest of the world does not have the capacity to stop perhaps millions of people. That’s just a fact.