How should the international community deal with North Korea?

Simply put, what else can the international community do except apply greater pressure to North Korea because it is a direct challenge. China, a powerful ally needs to use it's influence to turn the situation around. However it won't happen and they have their own reasons. In the end all North Korean wants is greater compensation from a overcompensating international community.

By seeing through their game.

Kim Jong-Un, like his predecessors, is indeed a rational actor despite the popular image otherwise. It's been a decades-long con: they flex whatever military might they have at the moment with the threat, "Hey, you better give us money, we're just crazy enough we might use this!"

And despite the fact that in recent memory they've never actually gone through with their threats beyond the most minor of provocations considering how many people they're technically still at war with, people buy into the con hook, line, and sinker. "Yes, you are crazy enough to start a war that you know you have no chance of winning and that would almost certainly result in the dismantlement of your entire regime! I'd better give you everything you want!"

Of course there are saber-rattlers opposed to North Korea who want to respond to DPRK's threatening gestures with threats of their own. That plays right into the regime's propaganda machine that convinces the public the world really is out to get "the best Korea" so the regime's aggression seems necessary.

The only solution is to quit playing their game. Quit buying into the lie that their leader is a madman as opposed to a spoilt boy who has been taught exactly how to milk their reputation to hold up their incompetently run economy. Impose real embargoes. Isolate them. If China wants to hold them up to avoid a stream of refugees flooding the border, China can do it alone. All it will do is prove the ineptitude of the North Korean philosophy of Juche in the first place. Sanctions will only be lifted when DPRK makes real, concrete action to fit into international norms, not vague promises that can be abandoned the next time a Kim Jong wants to throw a tantrum.

Simply put, what else can the international community do except apply greater pressure to North Korea

They can apply no pressure. Fake it, invite Kim to UN. That won't be the first nor the last dictator in there. Ask him to help in Syria, to host Olympics and all sort of useless projects that keep busy head of States. Flatter him into opening the oyster shell. The country needs a decade to get back to normal relations to the world and then topple the military and the Kim klan.

It hasn't worked in Russia or China, so what makes anyone think they know how to "change" NK?

Assassinate Chubsy or the US can apply a hell of a lot of pressure on China to quit helping them - period.

Actually NK is harmless. Just leave them alone and ignore them.

The real threat is China, a destructive force in the making.

There is no "international community". There is an ever-changing coalescing of interests. North Korea is irrelevant to Europe, while Japan wants to drum up support - and maybe "understanding" for military strengthening - by portraying North Korea as some kind of existential threat, which it is not. Meanwhile, other nuclear powers - some not even members of the NPT - are currently considered friends and their actions ignored, even rewarded.

How should the international community deal with North Korea?

Carefully

Essentially, North Korea is holding the South Korean capital hostage. Solution: Temporarily relocate the government functions of Seoul and evacuate the city, then impose a complete embargo until a cabal of Un-derlings takes out the lil' Un. Not easy or pretty, but effective.

I'd like to call NK harmless but I think those days are gone. If China agrees to stop NK getting fuel oil, that would definitely push them into a corner. Even their old tanks, submarines and planes need fuel. If not, a precision strike on their nuclear test site with conventional weapons may be necessary to get them to stop. Not wanting to be in favor of starting war but it's getting hard to see what any other realistic and effective options are.

a precision strike on their nuclear test site with conventional weapons may be necessary to get them to stop.

To get them to stop saber-rattling?

Just let them rattle. It hurts nothing other than some people's egos. Let's not start a war over ego.

Unfortunately, there is a limit to the patience of SK, Japan, the US and even China. You just can't keep lobbing missiles in the direction of other countries while ranting and raging.

Unfortunately, there is a limit to the patience of SK, Japan, the US and even China. You just can't keep lobbing missiles in the direction of other countries while ranting and raging.

Why not? As long as they aren't hitting the other countries, all they are doing is saber-rattling.

Just let them rattle. It hurts nothing other than some people's egos. Let's not start a war over ego.

Nuclear capability + long-range delivery system = serious threat

This isn't just about ego or rattling.

By applying trade sanctions to China. If China feels the hurt they will soon rein in the Fat Boy.