North Koreans work at a factory of South Korean-owned company in the inter-Korean industrial park in Kaesong, North Korea on September 30, 2009. (Ho New/Reuters)

North Korea has been making a lot of noise lately -- threatening to restart a nuclear facility, blocking South Korean workers from a joint industrial plant, even declaring a "state of war" with South Korea. Is it saber-rattling? Blustering? A credible danger? Here are six things to keep in mind about the country's threats so far, based on what experts know about the obscure Kim regime.

1. What happened on Wednesday?

More than 480 South Koreans and their trucks who arrived a border crossing to try to enter the Kaesong Industrial Facility in North Korea were denied permission to cross and had to turn back. This comes after North Korea threatened to shut down the complex entirely a few days ago.


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2. What is the Kaesong Industrial Facility?

It's a complex about six miles north of the border, where 121 mostly South Korean companies employ 44,000 North Korean workers. It opened in 2002 as a way of forcing cooperation between the two bitter enemies, and had the fringe benefit of supplying South Korean companies with dirt-cheap North Korean labor. Ever since, it's been seen as sort of a bellwether to determine North Korea's seriousness about its seemingly endless threats of war. An operational factory meant a (probably) bluffing Kim regime.

The companies there make everything from textiles to kitchen utensils, and the entire operation sounds like a strange amalgam of all the North's bellicose propaganda and all the South's stability and riches. "Though songs praising the ruling Kim family play on the factory loudspeakers, the electricity, water and sewage systems all come from the South, as well as the technology and the meals for workers. Products are shipped back to the South, where they are then exported to Australia, China and various other countries," the Washington Post reported .

3. Why is North Korea doing this?

The complex generates more than $92 million a year in wages for the North Korean workers, so it could just be a way for Kim Jong Un to prove that he doesn't need the South's paychecks to keep his country afloat.

They're also angry over the recent joint military drills between the U.S. and South Korea. In 2009, North Korea closed its border gate at Kaesong entirely over similar exercises, leaving hundreds of South Korean workers stranded in Kaesong for several days.

"There's talk that North Koreans need Kaesong for their economic well-being. This is a message for South Koreans that they can cut it off whenever they want," said Joel Wit, a visiting scholar at the U.S.-Korea Institute at Johns Hopkins University's School of Advanced International Studies. "It doesn't surprise me."

4. What about the nuclear facility -- is that a big deal?

On Tuesday, North Korea announced it's going to restart facilities at its Yongbyon nuclear installation. If they actually restart them, one of those facilities should -- in about six months -- be able to produce enough plutonium at least eight more nuclear weapons, "adding significantly to Pyongyang's existing small inventory," Wit wrote in Foreign Policy.

Though North Korea is unlikely to go to war with the South, any conventional war involving North Korea could go nuclear if the North feels like it has few other options, according to professors Keir A. Lieber and Daryl G. Press, who wrote about the incident in Foreign Affairs. That's a pretty terrifying prospect.

If war erupted, the North Korean army, short on training and armed with decrepit equipment, would prove no match for the U.S.-South Korean Combined Forces Command. Pyongyang's only other option would be to try to force a cease-fire by playing its only trump card: nuclear escalation.

5. So what should the U.S. do now?

Wit thinks the Obama administration should engage directly with the Kim regime.

"John Kerry should go to Pyongyang and meet with Kim Jong Un to see if there's any way out. We really do need to re-engage with North Korea rather than reacting to their moves," he said. "If there's a path forward that's peaceful and can get things back on a diplomatic track, the only way to do that is face-to-face contact."

Other North Korea experts think the key to reining in Kim's development of nuclear weapons is to assure him that if tensions escalate to war and the regime falls, his family will escape the same fate as Saddam Hussein or Moammar Gadhafi. As Lieber and Press wrote in Foreign Affairs:

American and South Korean leaders should urge China to develop "golden parachute" plans for the North Korean leadership and their families. Leaders in Pyongyang will keep their nuclear weapons holstered during a war only if they believe that they and their families have a safe and secure future somewhere.

6. How worried should we be in the meantime?

Medium-level worried. It's not really in the best interest of the North to go to war with South Korea/America, and the country has long had nuclear capability, so that development in itself is not much of a game-changer.

The Kims have also repeatedly threatened to shut down Kaesong in recent years.

"[Kaesong] is another page out of the North Korean playbook," Wit says. "That doesn't mean it's insignificant, but we shouldn't be rushing to the conclusion that war is imminent. It's a tense situation, and in this kind of environment, a miscalculation could result in escalation."

What we should really watch for is if North Korea prevents the South Korean workers from leaving Kaesong, which could be interpreted by the South Korean government as a hostage situation, says Stephan Haggard, professor of Korea-Pacific Studies at the University of California, San Diego.

"Everything else," he said, "is just talk."