On the border of brinkmanship

With its nuclear test and worldwide isolation, North Korea turns the last remaining Cold War front into a first-rate hot zone | Mindy Belz, Becky Perry

At the edge of the Demilitarized Zone (DMZ) that separates North and South Korea, tourists peer into the residual morning fog. South Korean soldiers in combat fatigues patrol a concrete balcony, enforcing the yellow no-photo line painted on asphalt tiles. A stretch of spiraling barbed-wire fence snakes through the lush valley below. Barely visible on the other side: the border with North Korea.

With countless landmines strewn but obscured in the Korean buffer zone, the most heavily fortified border in the world embodies the converse of the Berlin Wall: The DMZ is a vast expanse of danger and suspense rather than a marked-off line of physical demarcation. By arming itself with nuclear devices, North Korea has escalated political turmoil not only on the Korean peninsula but throughout North Asia and the world. Here the DMZ remains a tangible, daily reminder not only of past conflict but of the present standoff.