Demilitarized Zone (DMZ) counter-agent patrols are a necessary part of South Korea's defense against infiltration from the Communist north. The men of A Company, 1st Battalion, 9th Infantry Regiment, 2nd Infantry Division search the rugged terrain by day for evidence of infiltration and stakeout in defense ambush positions by night. Moving through the open country they watch the ground as carefully as they scrutinize the trees ahead. Sgt. Richard "Tex" Ritter, a Vietnam veteran now with A Company, shows other members of the patrol how to "read" a North Korean footprint. 1st Lt. William Madigan, A Company patrol leader [not pictured] says he has several sergeants in his patrol with Vietnam experience. their knowledge of tracking and ambush tactics helps make the patrol a more effective deterrent to North Korean infiltration. "The Vietnam vets help give the other men confidence also," he says.