North Korea barred South Korean workers from entering a jointly operated factory on their border Tuesday, the latest in a series of provocative statements and actions by the secretive regime. (Read an overview of how the situation has developed here.)

Previously, South Korean firms were permitted to employ North Korean workers at the factory, as The Washington Post’s Chico Harlan reported from Seoul:

The move is significant because the Kaesong Industrial Complex — located six miles north of the heavily fortified border — has long stood as a near-untouchable symbol of cooperation, operating even during a pair of fatal 2010 attacks launched by the North on the South. . .

Experts say the North is likely reluctant to close the complex and is instead hoping to spark alarm from its richer neighbor, whose people typically view Pyongyang as a worrisome but far-removed threat — one unlikely to upend their own lives.

Last week, The Post’s World Views blogger, Max Fisher, had argued that because Kaesong remained open, the North was bluffing. Although the plant is now closed to the South, Fisher thinks the situation hasn’t changed:

Does this mean that war is now imminent? Well, no. It’s still very much in North Korea’s interest to avoid war; this move is likely just a provocation. This is also not the first time that North Korea has closed the plant, and previous closures have been brief.

Like Iran, another state seeking nuclear weapons, North Korea continues to resist international calls for it to abandon its nuclear program, Fisher says:

Amid more bellicose threats from North Korea and on the eve of a new round of talks with Iran, neither the administration nor its Asian and European allies appear any closer to resolving either case.

North Korea brought the Obama administration’s difficulties into sharp relief Tuesday by announcing that it would restart a shuttered nuclear reactor at its Yongbyon facility and increase production of nuclear weapons material.

Fisher believes that the decision to restart the reactor suggests North Korea tested a plutonium weapon in February, not one containing uranium, as many observers had worried. He writes at World Views:

It’s still possible that North Korea did succeed in developing a uranium weapon and that its February test was a uranium warhead. We don’t know for sure. But the big effort to rebuild and relaunch its plutonium plant (it destroyed the reactor in 2010 as part of the peace deal), despite the diplomatic costs this will certainly incur Pyongyang in any future international talks, suggests that the country really, really wants more plutonium.

He also writes that despite Pyongyang’s behavior, there are no indications it is mobilizing its military, and the regime’s warmongering may simply be domestic propaganda:

North Korea doesn’t want to start a war because, among other reasons (example: it would lose), it’s happy with things the way they are now. And if things are going to stay the same, Pyongyang might as well try to take credit for that, by presenting the U.S.-South Korean military exercises as a big scary military threat that only ended without war because Grand Marshall Kim Jong Un successfully stood down the American imperialists.

Perhaps as part of that strategy, the North released a photo showing military leaders studying purported plans for attacking U.S. cities. For some reason, the plans included Austin, Tex. Twitter users from the city were unfazed, though they wondered why they’d been slated for destruction.

Separately, Pak Pong Ju, a North Korean official with a reputation for supporting economic liberalization, became the country’s premier over the weekend. But Fisher warns against undue optimism:

How big of a deal is this? Is Kim Jong Un signaling his desire to finally open up North Korea to the world? Sadly, we should probably set our expectations for “reform” pretty low. . .

Perhaps the best reason to suspect that North Korean reform is not just around the corner is the fact that it could undermine the state ideology. Kim’s father and grandfather, Kim Jong Il and Kim Il Sung, are played up constantly in North Korean propaganda as the godlike architects of their country’s flawless system. As Daniel Pinkston of the International Crisis Group wrote, “Reform in [North] Korea would require questioning what the greatest geniuses in history did wrong, and then changing it.” This is not a system that is equipped to handle change.