iMSD6pHQd.SIWinter drills on either side of the demilitarized zone underscore the fragility of a potential thaw between North Korea and South Korea after Kim Jong Un raised the possibility of a summit. In a snowy valley 150 kilometers (93 miles) east of Seoul, South Korean commandos in white camouflage rappel 30 feet from a Black Hawk helicopter, detonating a bomb in an “enemy” building before wading through an ice-covered river. Annual extreme-weather drills are also being held by North Korean troops across the heavily fortified border that bisects the peninsula. “This operation is aimed at striking essential enemy facilities,” South Korean Major Jeong Sung Wan said at the exercises on Jan. 8, his face covered in black and white camouflage paint as smoke rose from the bombed building behind him. “With enough training we will blow up any enemy facility in any given mission no matter what the cost is.” The mention by Kim in his New Year speech of a possible summit with South Korean President Park Geun Hye has done little to ease military tensions between two countries that remain technically at war more than 60 years after outright conflict ceased. Even as Park says she’d meet Kim without preconditions for talks, South Korea has warned his regime is building a network of infiltration posts and progressing on miniaturizing nuclear warheads. More