South Korea has described its northern neighbour as a "serious threat", in the wake of its nuclear test in October. A defence white paper said North Korea's nuclear capability along with its land army and conventional weapons had raised the threat to the South.
The assessment uses the strongest wording since Seoul began a policy of engaging with Pyongyang in 2000.
Talks aimed at dismantling North Korea's nuclear programme ended in deadlock in Beijing earlier this month.
In its biennial white paper, South Korea's ministry of defence said the threat from the North had risen, although the country was not yet a full-fledged nuclear power.
"North Korea's conventional forces, its nuclear test, weapons of mass destruction and the forward deployment of troops are a serious threat to our security," the report said.
The North had obtained an estimated 30kg of plutonium - enough for five nuclear bombs - in the past three years, while its total stockpile now stood at 50kg, the paper said.

More than 70% of the North's ground troops and some 40% of its 820 fighter jets were deployed close to its southern border, it added.
Two years ago, the defence ministry called the North a "direct military threat".
North Korea triggered international alarm - and ensuing UN sanctions - as well as stoking regional tensions when it tested a nuclear weapon on 9 October.
Following its test, Pyongyang agreed to return to long-running multi-national talks, after walking out more than a year ago.
But despite five days of intense negotiations, the talks, hosted by China, ended without agreement just before Christmas.

As this article shows,NK is hungry land but still threat to world security and stability.
You must be worried if NK sell N-weapon to Iran.

Resign of US Ambassador to the UN John Bolton was a great missing.
He was a rare person who can put forth sound arguments.
I know it,UN can't take any　countermeasure against NK　now.
I'm still wondering　why reform is very difficult anywhere anytime・・・・・・・

The nukes get the headlines but it's their Chemical and Biological arsenal that's really worrying. No one talks about them but they have it in plenty and it's going to kill a LOT of people.
"military that accommodatets oneself to public causes nation's ruin,public that don't understand military causes history's ruin. "
That's a good quote. It's what's happening in South Korea now... the Marine Corps is pretty much no more. If the North invades, we will be a very very small factor in the outcome.

North Korea has always been the Threat, as North Korea has little if anything to lose.

North Korea likes the idea of the US being tied down in Iraq, gives North Korea more chips in the big game.

There will come a day when North Korea (like the USSR in the past) will wish they had not pushed so far.

What exactly is in their chemical and biological weapon stockpiles?

It's getting more and more nerve-wracking to wait for them to make the move, and I live in the USA. I can only imagine what it must be like for the South Koreans on the DMZ, knowing that at any moment the North could flip out and start a war.

The US Military in South Korea views itself as merely a Speed Bump, just trying to slow the North down should the North Koreans ever pull the trigger.

As for their Chem/Bio Stocks, well, it's a safe bet that they have more than Saddam ever had, in his entire life, and seeing how everyone was so up in arms over Saddam, even when he no longer had his Chem/Bio WMD, I'd say there are lots and lots of people who know just what the North Koreans are sitting on, and it scares the hell out of the people in power, almost as much as it scares the hell out of the Troops on the ground in South Korea. So much so that we dare not go against North Korea.
Which we will not do anyway, seeing how we worry about Seoul, the South Korean Capital, the Capital danger close to the DMZ, the same Capital that the South Koreans were supposed to move years ago, but never got around to it, sadly.
Now there is no way to get all the millions of Civilians out of Seoul should we want to hit North Korea in a Preemptive Strike, and there's just no way to kill all the North Koreans before they retaliate on Seoul.