China does have large Navy and it is beefing up it's navy in fact many others are also doing the same. I am talking about a short term future scenario here.
I said if? Because you can't defeat them if you can't defeat the USN and USAF? I said if you defeat them in East Europe and the Mediterranean than nothing will be able to prevent you from North America period?
Taking out the Carriers is not much of a chellenge as many would like to assume in this age and time now that being said. When you defeat them in Eurasia and ofcourse including their Navy and airforce than there is nothing they could do to prevent the opponent putting troops on US soil at will.....
They could do nothing to prevent it zero, nada and absolutely nothing this is just a conventional reality
Future scenario is highly speculatory. WE shall consider current force compositions of all countries involved.
You mentioned China (a pointer). WE need to look at how many amphibious assault ships there are in the inventory of Chinese navy and what each type can do.
Aircraft Carriers = 2 active (Type 001; Type 002)
Amphibious Assault Ships = 6 active (Type 071 = 5; Type 075 = 1)
Type 071 troop transport capacity = 800
Type 075 troop transport capacity = 900
China can realistically transport about 6000 troops with a small number of tanks and armored vehicles to American soil. This force is not sufficient to handle one state of USA, let alone entire USA. And will it even get through the USN to begin with?
Defeating NATO in Europe is another 'assumption' (a matter of IF again). I pointed out to you that Russia is not up to the task by itself and Russian allies will have to dispatch a large number of troops to European borders for the needful. This will take a while and NATO can disrupt a military buildup near European borders with its rapid reaction forces.
Europe is also very large with numerous geographical features which can bog down an invading force and some of the European countries can roll out different types of weapon systems themselves. UK, France, Germany, and Sweden are well-known in this respect. Others can contribute on some counts as well. These are technologically advanced countries on average. Full-scale war in Europe will take a substantial toll on the Opposing Camp as well. There will not be much to spare for USA afterwards. This is something which continues to allude you.
Taking out Aircraft Carriers is not much of a challenge? American at that? Are you for real?
American Carrier Strike Groups (CSG) are composed of multiple well-armed ships, airborne assets, and submarines in wartime conditions and networked to incredible levels (CEC). Each composition can can create a substantial surveillance field, resist jamming due to CEC, intercept volley after volley of different types of missiles, and knock out hostile forces from respectable distances - all at the same time. I am not sure what some members of the forum are thinking.
Sorry dear but all that tough talk is cheap.