President Barack Obama visits U.S. military personnel stationed at Observation Post Ouellette along the Demilitarized Zone (DMZ) which borders North and South Korea, outside Seoul, March 25, 2012. President Barack Obama visited South Korea's tense border with the North on Sunday in a show of solidarity with U.S. ally Seoul and a message of resolve to Pyongyang's new young ruler in his country's nuclear standoff with the West. REUTERS/Larry Downing