During the Vietnam War, Duayne Keen battled with the U.S. Navy Seabees south of Da Nang. Way south. "I was right on the South Pole," noted the Conestoga man, who fought numbing Antarctic temperatures ...

But when the Japanese attacked Pearl Harbor on Dec. 7 of that year and the United States was thrust into war, the call went out for skilled tradesmen to join the Navy, so as to become part of the sea ...

In the midst of a catch-as-catch-can war that has placed a premium on mobility and speed, a World War I style line of defense is creeping inland from the South China Sea Coast just south of Da Nang.