Does the United States have enough firepower to fight China and North Korea if need be, and which weapons of war would be used?

Answer 1

Sure, but not win.  At least not conventionally. 

Answer 2

The war today is being fought with computing power and state bot farms. Your home computer is probably part of a Bot network helping with the little tasks that need to be done. You were infected while you were looking at something harmless or maybe something erotic, whatever. The Bot farms have learned not to "kill the Golden Goose" by over-tasking the infected units.

Answer 3

The US Navy is all set to fight WW TWO again with lots of carriers.   Take out the carriers and the US Navy is pretty much left with small ships and subs.   The easiest way to take out the carriers is with a long range missile with a tactical nuke on it.   They can do that from a thousand miles a way and probably would wait until they are at sea so we do not have an excuse to claim they are attacking our cities.    After that we will have to decide if we want to expand the war or to sue for peace.   Considering how the USA has not really won a war since WW II,   I think when it gets real heavy we will sue for peace.  

Answer 4

One SSBN (Missile Submarine) can handle both countries. Each SSBN carries 24 Missiles and each Missile carries 10 War Heads.   Two War Heads for North Korea would be sufficient, the rest on China.  Nothing would be left.

Answer 5

As Sam wrote, it's an economic war. It's been going on for a while. Recently, it has moved into an overt cyber war. Since 2016 or so, the Russians have been conducting cyber and information war on the US with an aim to destabilize the US and weaken it to the point that Russia can do pretty much what it wants.

Answer 6

You are fighting the wrong war. It's the economy, not military

Answer 7

Not with conventional weapons. North Korea by itself would be no problem. But China is a different matter. The US could take them on only to the point of possible containment, but not to invade them.