Relations between the two Koreas took a sharp nose-dive in 1976, when two American soldiers were killed by a pack of axe-wielding North Koreans. The cause of the trouble was a poplar tree which stood next to the Bridge of No Return: a UNC outpost stood next to the bridge, but its direct line of sight to the next Allied checkpoint was blocked by the leaves of the tree, so on August 18 a five-man American detail was dispatched to perform some trimming. Although the mission had apparently been agreed in advance with the North, sixteen soldiers from the KPA turned up and demanded that the trimming stop. Met with refusal, they launched a swift attack on the UNC troops using the axes the team had been using to prune the tree. The attack lasted less than a minute, but claimed the life of First Lieutenant Mark Barrett, as well as Captain Bonifas (who was apparently killed instantly with a single karate chop to the neck). North Korea denied responsibility for the incident, claiming that the initial attack had come from the Americans.
Three days later, the US launched Operation Paul Bunyan, a show of force that must go down as the largest tree-trimming exercise in history. A convoy of 24 UNC vehicles streamed towards the plant, carrying more than 800 men, some trained in taekwondo, and all armed to the teeth. These were backed up by attack helicopters, fighter planes and B-52 bombers, while an aircraft carrier had also been stationed just off the Korean shore. This carefully managed operation drew no response from the KPA, and the tree was successfully cut down.