North Korea had its fifth nuclear test last Friday. Here's what we know so far.
Q: What happened? Was it really a nuclear test, like North Korea claims, or was it just an earthquake?
A: Yes, it really was a nuclear test. The US Geological Survey said the 5.3 magnitude seismic event it recorded had "explosion-like characteristics" and occurred where North Korea has tested nuclear devices in the past. The North’s first nuclear test was in 2006, and three have been carried out since Kim Jong Un took power in late 2011.
Scientists knew it was an explosion the the waveform is sudden, unlike an earthquake, and the depth is shallow. Plus, it happened at a known North Korean nuclear test site.
Q: So this means they really have a nuclear warhead capable of being fitted on a long-range missile?
A: Not necessarily. North Korea announced that they had conducted a "nuclear explosion test" and that they had "standardised" a nuclear warhead. Just because they're right on the explosion doesn't mean they’re right on the standardisation.
Making a nuclear warhead small and light enough to fit to a missile is difficult. Army chiefs think North Korea is well on the way to doing this, but there’s no sign they are there yet.
And, even if they do manage to "miniaturise" a nuclear device and stick it on a missile, there’s still a whole lot more steps to go through. A nuclear missile goes through extremes of heat and cold, shakes with vibrations during launch, and has to survive re-entry and hit its target. There’s a lot of things that can go wrong there.
But North Korea is making a lot of progress on its missile programme. And its latest nuclear test does show they have takanother step down the path to what some people think is Pyongyang’s ultimate aim: being able to send a nuclear-tipped missile to the U.S. mainland.
Q: If that was supposed to make me feel better, it hasn’t worked.
A: Sorry about that. But it's true that this is a pretty scary situation. Kim Jong Un has made it clear he's determined to make North Korea a nuclear state - and he’s certainly shown no sign to return to diplomatic talks aimed at getting him to give up his weapons programmes. The example always cited in North Korea is Libya. Moammar Gadhafi gave up his nukes and look what happened to him.
North Korea is still technically at war with South Korea, the United States and the United Nations since the 1950 - 1953 Korean war, in which only China was on its side. While that war has had a ceasefire there has never been a surrender.
In his 2002 State of the Union address, then US President George W Bush named North Korea alongside Iran and Iraq as an "axis of evil" and a year later, the US and Iraq were at war.
Q: Where are the Chinese when we need them?
A: Well, China is one country that has real power over North Korea, given that it gives economic aid to its neighbour and is its main route for trading with the rest of the world. China is always concerned about peace on its borders and has shown itself to prioritise keeping North Korea afloat over punishing Kim.
That said, China seems pretty angry right now. North Korea fired three missiles lastMonday while Chinese president Xi Jinping was hosting the Group of 20 summit in Hangzhou - and those missiles were technically capable of hitting Hangzhou. It's hard to miss the message Kim was sending.
On Friday, China’s foreign ministry released a statement condemning the test and saying it would work with the international community to urge North Korea to return to talks and give up its nukes.
The question now is whether China gets serious about enforcing sanctions.
Q: Why is all this happening now?
A: Friday marked the "Day of the Foundation of the Republic" - a public holiday commemorating the 68th anniversary of the formation of the North Korean government by Kim Il Sung, North Korea’s founding president and the current leader’s grandfather. So it's an important day for the country.
But the test could also have been timed to push back at people thinking the government is weak because some high level officials have run away to the west.
It could also be a signal to the outside world that North Korea won’t back down. The US will send an anti-missile weapon to South Korea, and China has been supporting UN statements "deploring" North Korea’s recent actions. This is Kim Jong Un’s way of saying, "you’re not the boss of me."
Q: What happens next?
A: Japanese "sniffer" planes went up Friday and there are probably some American ones flying around, too. They’ll be trying to measure radiation levels and capture gases so nuclear scientists can know more the test.
Then, it will be back to the UN Security Council. Today, North Korea’s Foreign Minister Ri Yong Ho left Pyongyang to meet UN officials in New York. We can expect meetings and harshly worded statements out of the United Nations, and a push for more sanctions. But the question is: What else can the international community do? There have been lots of new sanctions imposed this year - a crackdown on mineral exports, increased cargo inspections, tougher financial limitations - and clearly none of them have made Kim Jong Un stop holding the missiles and the nuclear tests.
There aren’t many other options. A military strike is out - no one has any appetite for another war, and striking North Korea would probably unleash a volley of artillery by the North across the Demilitarized Zone at Seoul, home to 20 million people.
There's another option: flooding North Korea with trade and investment and information and trying that way to convince them to change. But with all this defiance, there’s even less appetite for engagement than there is for military action.
Meanwhile, Seoul says North Korea is preparing for another nuclear test.