There's intense speculation on the reclusive country's next moves after it claimed it successfully tested a hydrogen bomb for the first time.
North Korea stunned the world with what it said was the successful detonation of a miniaturised hydrogen -- or 'H' - bomb.
Describing it as "of unprecedented big power", it claimed it was also small enough to be loaded onto a long-range missile.
It's the country's sixth nuclear test since 2006: the first five are thought to have been atomic bomb tests.
"Well what's different is that this is a high-yield hydrogen bomb rather than a low-yield atomic bomb. An A bomb of 1 kiloton or 10 kilotons could destroy part of a city. A hydrogen bomb of hundreds of kilotons could destroy a major metropolitan area."
John Pike is a US-based defence analyst and Director of GlobalSecurity.org.
He's been observing nuclear proliferation for over 50 years.
"I think that the bottom line is that a hydrogen bomb is just not that hard to do. You need the basic design ideas, which have been around for a long time. You need the materials, easily within the reach of even the smallest nuclear power. And you need computer power. The early H bombs were built with computers that have far less computing power than this iPod that I'm talking on right now, so I don't see there's any real barrier to North Korea building H bombs, and If you look at the photographs that have been released Kim Jong Un is certainly admiring an object that looks like an H bomb is supposed to look."
Yang Mu-jin, Professor at the University of North Korean Studies in Seoul, believes the North Korean leader wants to put his country on a *level playing field with the United States.
"Nuclear weapons are the Kim Jong Un administration's means of survival. Simply said, North Korea's strategic intention is that as a nuclear power state, they are going to negotiate on an equal stance with the US. Also, it tries to highlight Kim Jong Un's military leadership so that he can counter US President Trump at any time in order to unify the country."
But Professor Yang believes it could be a risky strategy.
There's a possibility, he says, that North Korea could carry out a plan to stage what he calls "enveloping strikes" on areas around the US Pacific territory of Guam -- and that could lead to possible retaliation from the United States.
"If North Korea mistakenly fires at a wrong target and strikes Guam's territorial waters or its inland, it is difficult to rule out the possibility of a military counteraction by the US. However, when we look at North Korea's enveloping strike plan on Guam, the plan is well calculated in order to not abide by related international rules, so it will be difficult for the US to actually carry out a military counteraction."
While the international community turns to the United Nations to increase the pressure of sanctions against North Korea, John Pike sees this potential scenario.
"I think there's going to be a lot of chest-thumping. I think there's going to be a re-examination of the adequacy of missile defence systems. And I think there's going to be a continual discussion about the possibility of reintroducing American nuclear weapons onto the Korean peninsula. South Korea and Japan are going to talk about getting nuclear weapons."
He says the world should be scared of the potential for nuclear conflict, but believes reactions at present are somewhat over-excited.
"The bottom line is that North Korea might be the first country to use nuclear weapons in this stand-off but it won't be the last. That will be up to the Americans and after it's over North Korea will cease to exist. Kim Jong Un is not stupid - he's certainly evil but he's not stupid and he's not crazy. He's only going to use these nuclear weapons for deterrence to persuade the Americans not to attack him. There's no way he could credibly tell the Americans to evacuate South Korea or else he's going to nuke Los Angeles. That's not a credible threat because he knows how that would end."
