Up until a few days ago I was confident with America`s place in the world. An unshakable rock that was impossible to invade (unless Canada or Mexico go on a tangent lol). That China was an economic threat and possibly a military one but they could never actually win a ground war with America, especially on American soil. Then a thought struck me...(well several thoughts):
Invasion via cargo ships...
Think about that. Every year THOUSANDS of cargo ships dock in American ports to unload thousands of train car type boxes of goods onto our shores. They dont get inspected until they land (and those are very sporadic and half hearted). Now think about this. China could load over a million soldiers, vehicles, hell even helicopters onto several dozen of this ships and simply hide them in the cargo containers or below deck. They dock and once they all arrive BAM! 5+ of americas largest coastal cities are overun by a massive chinese surprise attack, while simultaneously china launches missiles to take out our communication and spy satellites. America would be crippled and even if we drove the chinese forces out (and we would never get all of them, there would be bands over them roving the countrysides and unpopulated areas of America for years, possibly decades causing havoc) we would be going to war with an enemy has has us by the nuts. They make most of the stuff that goes in our jets, tanks, and other tech. Once our crap starts falling apart were screwed even worse because we cant get more parts.
Now if China did this the rest of the world would be forced to go to war with them. (China+NK vs EU, russia, India, Japan, SK, Canada, latin american countries, and a few African nations). But honestly i doubt the EU would help much, they would likely look to their own defenses and start building Maginot line crap in Eastern Europe and Russia would be pummeled into the ground by an enemy with even more cannon fodder in their army than they have. The other Asian nations would last for a while but they would also be crushed by the massive numbers. The african/South American countries that joined in wouldnt be able to do much at all.
America would be reeling from the attack and crippled.
IF the Chinese did this i believe the war could go either way.