On the morning of Aug. 18, 1976, a work detail entered the Joint Security Area (JSA) at Panmunjeom to perform what should have been a routine task: trimming the branches of a poplar tree. Within minutes, two U.S. Army officers were dead. Capt. Arthur Bonifas and 1st Lt. Mark Barrett were killed by North Korean guards during a confrontation that lasted only a few minutes. Several other American and South Korean members of the detail were also injured. This Aug. 18 marks the 50th anniversary of their deaths. The event became known as the Axe Murder Incident, one of the most infamous confrontations in the history of the Korean Demilitarized Zone (DMZ). I can still remember when it happened. In August 1976, I was in the U.S. Air Force attending technical training school when I first heard about the killings at Panmunjeom. Korea was far away, and I could not have imagined that the events unfolding there would remain with me for the next half-century. But 50 years later, I find myself returning once again to that tree. To understand what happened on Aug. 18, it is necessary to know what was diffe