Heres my opinion on the situation. The U.S. would undoubtedly win. China would have to play defense. The US would already have the invasion forces ready. We've got this invasion shit down to a science. China may have that new missile and a few other tricks up there sleeve. But all and all they're not bout it. Their massive population don't mean shit. If anything its a handicap. You have to remember only 70 years ago the tiny island of Japan was man handling them and raping them of all their natural resources. Those billions don't mean shit. Also you'd have to think about who would align themselves with America for their own personal gain. N. Korea, Japan, India... And I'm sure the Brits wouldn't mind getting Hong Kong back. After we get Allies the next thing we'd do is Blockade any and all imports. Being as though they have that missile we'll park our surface fleets at the minimum safe distance and send in fast attack subs to enforce the blockade. On land we'd surround their borders with our Army and have the Air Force back them up. So then the Chinese would have to rely on its own resources to feed its MASSIVE ARMY and POPULATION. And remember the US practices "total war", we haven't done it in a while but believe we'll pull out that playbook quick if we need to. And as far as those missiles we'd fly EA-6Bs and E-2s all night, Jamming most air and ground defenses. Sneak a few of our own professional saboteurs in their on a HALO night op, I'd say two to three Seal platoons would be enough to takeout the 21D munitions plants and once those are gone it'll be a free for all. But judging by previous actions of Asians during the past century as far as military strategies they'll dig in and fight for a while. We'll bomb them around the clock with the world's two biggest air forces. The US Air Force and the US Navy. Start amphibious assaults along the coast with the Navy and Marines. Start pushing forward from the northwest with Army mountain divisions. From the southwest come in with the tanks. They'd have too much ground to protect with not enough modern roads throughout the country to be effective at moving troops to unpopulated locations. Which gives us free range to start setting up bases on inland China and once that happens it'll be endgame. From that point on all they have is the threat of a nuclear strike which they won't use until they've lost at least 25-30% of their army and land. Which at that point we'll ignore until we take about another 10 % of their land and then offer them a Surrender package which states they'll forgive all US debt while taking on more US debt for that current war and us taking a sizable chunk of their land for permanent US military bases and vacation spots. The End.
Look at the map of China, USA have no chance. Even right now china is locked, who in hell can sneak in to cause major damage??
There is no way USA can not win a war with China.