We didn't think it was possible, but the North Koreans found a completely new way to threaten the South—but this one might actually affect the lives of some people who live below the DMZ. The North shut down its last military hotline to South Korea on Wednesday. It's a move they've pulled before, like when they shut down a Red Cross communication line earlier this monthBut the difference this time is that this hotline actually helps South Korean workers on a daily basis and loss of communication may strand some of them north of the border.

The two nations jointly operate a large industrial park in the Northern city of Kaesong, just on the other side of the line of demarcation between the two nations. The park is financed by Southern money and employs mostly Northern workers, but around 900 South Koreans cross the border everyday to go to work there. The phone lines they turned off today are used to control the border traffic and avoid flares that might involve the military. The last time the North cut this particular hotline, in 2009, 80 South Korean workers were left stranded above the border for a more than a day. The Kaesong factories are the last serious form of cooperation between the two countries.

Tuesday also marked the three anniversary of a torpedo attack by the North that killed 46 South Korean sailors.

South Korean officials report that cross-border traffic appeared to be moving normally for now, suggesting that the North isn't actively blocking the traffic yet. But since the North's stated excuse for turning off the hotline is that "war may break out any moment, [so] there is no need to keep North-South military communications," then things could change at, well ... any moment. Pyongyang has spent the last month finding new and creative ways to threaten the world—they even threw in a warning today for the South's president, Park Geun-hye, to "watch her tongue"—but so far have shown no signs of actually firing the first shot. We eagerly await a fresh new threat of fiery doom tomorrow.