Until 1976, there was complete freedom of movement by all sides with the limits of the JSA. After the Axe murders of August 18, 1976 and subsequent Operation Paul Bunyan, the Joint Security Area became divided, separated by a concrete threshold approximately 17″ X 5″ which represents the border between North and South Korea.
After the enforcement of the MDL (military demarcation line) however, the North Koreans no longer had a way into the JSA and, within 72 hours, built what has now become known as the “72 Hour Bridge” (or “Bridge of 72 Hours”).
Chapter 12 of MG John K. Singlaub’s book Hazardous Duty tells what happened after Operation Paul Bunyan:
We heard nothing from the North Koreans until noon, when they requested an impromptu meeting of the Military Armistice Commission. The senior North Korean Army officer glumly read a message from his Supreme Commander, Kim Il Sung. The Communist dictator expressed “regret” over the August 18 incident and hoped that both sides would make efforts to prevent similar unfortunate outbreaks. This was the first time in the twenty-three year history of the Armistice Commission that the North Koreans had acknowledged even partial responsibility for violence along the DMZ.
Over the next several days, satellite and aerial reconnaissance revealed the North Koreans were still on a defensive posture. Slowly they reduced the high-level alert, still obviously wary of American forces in the region. We scaled back at the same pace, again reminding the Communists of the size and flexibility of our ground, air, and naval forces. In early September, the Communists agreed to remove their remaining guard posts from the southern sector of the JSA. We then extracted a further concession by requiring they construct their own bridge into the neutral zone.
In the JSA, the net result of the operation was the physical separation of UNC and North Korean guards. We were careful to coordinate our negotiations with military operations. The slow reduction of augmented naval and air forces followed each North Korean concession. On September 8, when the North Koreans agreed to virtually all of our demands, the JCS gave the order to reduce alert level back to DEFCON-4, and the USS Midway departed Korean waters for Japan.
Operation PAUL BUNYAN was a valuable reminder that North Korea’s ruthless and increasingly desperate Communist leaders could be effectively dealt with only from a position of strength. They viewed our earlier reconciliation attempts as weakness to be further exploited. The only reason Kim Il Sung finally backed down was that we made him understand the danger he faced. Despite our retreat from Southeast Asia, America had stood solidly beside our South Korean ally.
Chapter 12 is available on line at:
Thanks to Robert Poorman for his help in finding photos of the 72 Hour Bridge.