One can't underestimate the passionate longing felt by most Koreans on both sides of the Demilitarized Zone (DMZ) for some form of reunification – or at least reattachment – of the two nations. Amazingly, the 1950-53 Korean War has never been ended by a peace treaty so a simmering state of war exists between North and South Korea in spite of past attempts to end it. During the war, 33,686 Americans died and 128,600 were wounded, and the two Koreas suffered over 2 million dead. Chinese casualties were heavy.
The DMZ is probably the most heavily militarized frontier in the world, with hundreds of thousands of tough troops and thousands of tanks and guns confronting one another. I've seen few more impressive military sights. Only the Pakistani-India border in Kashmir offers a similar martial display and menace.