They couldn't even take Vietnam. The US military is the strongest military in the world, but that doesn't mean they can take on anybody. China can take out anything the US throws at them. The thing is that you have to actually get your forces somewhere to get in a fight. In the case of North Korea or china, that means crossing the pacific. Which is no easy thing to do with a lot of forces. The bloodiest battles in WW2 apart from Stalingrad were fought in the pacific. But even if the US can manage it, China has all of its forces right there on the continent. It's easy as fuck for them to fight off any kind of invasion, doesn't matter if by infantry or drones. Not only does China have access to technology, they also far surpass the US in terms of manpower as well as production capacity. China can pump out 10 tanks in the same time the US produces one, just as an example. So if China wants to defend North Korea, the US don't stand any chance at all. We already saw it in the 50s and since then China has become stronger while the US has become weaker. By now I wouldn't be surprised if the north supported by china took the south if another war would really break loose.

People seems to think that simply having better weaponry makes winning a war easy. Afghanistan and Iraq were supposed to be easy too. NK is way better armed, has a large army and people ready to die if the Supreme Leader says so. It's not like they have a good shot at defeating a US invasion, but this war would be costly and long. And it can only happen if China gets tired of Jon-un's stubborness and decides to abandom them to their own luck. This is quite hard since China won't want to "help" South Korea and Japan by doing so, it will happen only if NK commits a imbecile act of aggression against the US.

Even for the US, this situation could be catastrophic. If NK, with quite a bit of luck, managed to hit a US navy cruiser with a nuclear bomb, the US would face the dillema they always intended to avoid: nuclear counter-attack or not? Would they use nuclear weaponry so close of China and SK? Would it be considered a war crime since civilians would be attacked? But in the case they didn't used nukes and simply attacked NK with massive brute force and conventional weaponry, enough to basically destroy the place, it could send a message to other superpowers that you are allowed to strike the US with nuclear weaponry and they won't counter immediatily. They don't want Russia and China to think that the US wouldn't respond with nuclear force quickly, so maybe a full strike could be feasible.

Realistically, the US will wait for China to get fed up with NK or for them to attack first (so China won't back them up). Then they will try to make Jon-un look like a fool and maybe start up a small revolution with CIA. When the government falls, SK will just unify with NK. The US would probably give them loads of cash so they can fix the famine/economic issues in the North. China would be pissed, but they are probably seeing that NK is becoming more of problem than an asset.

The Iraq war was easy. It was trying to defend it from terrorists post war that took forever. Being we aren't allowed to kill civilians, our enemies best bet is to not wear uniforms or try to out do us as far as tanks or planes and navy vessels, it's to blend in with their civilians and take pot shots at us. Look at Afghanistan as well, that wasn't even a conventional military vs military war. In a war like that (military power) we would decimate in a matter of no time.

The war wasn't over until the US left Iraq. It officialy lasted 8 years. NK would absolutely use civilians as shields. Hell, they would probably give guns to children so US soldiers would have to shot them. So, compared to Iraq, they are better armed, have more soldiers, are completely obsessed with their leader (a good portion of Iraq population was against Saddan) and will act with total disregard international laws with way more ease. It would be an ugly war, for sure.

The only "easy" wars we have is when someone quits. Like Gulf War. For millions of North Koreans, Jong-un is a god. I wouldn't count on them quitting.

The Iraq war was easy. It was trying to defend it from terrorists post war that took forever. Being we aren't allowed to kill civilians, our enemies best bet is to not wear uniforms or try to out do us as far as tanks or planes and navy vessels, it's to blend in with their civilians and take pot shots at us. Look at Afghanistan as well, that wasn't even a conventional military vs military war. In a war like that (military power) we would decimate in a matter of no time.

100% agree