On December 15, 1950, with the Korean war at its height, Private David Strachan of the Royal Northumberland Fusiliers was put aboard a truck for an urgent mission.
Korean troops had been seen shooting civilians - including women and children - north of Seoul. A company of Fusiliers sped to the scene. 'We knew what we were going for, but a lot of us didn't believe the rumours,' said Mr Strachan. 'When we got there, it was true.'
Lines of civilians were kneeling in front of trenches; behind them, masked men with carbines were preparing to shoot.
A British officer demanded that the Korean in charge halt proceedings. The man responded by pointing a pistol at the Briton. The Fusiliers began to fix bayonets. The Koreans backed down, and further atrocities were prevented.
The killers, however, were not the North Korean enemy. They were members of the South Korean security forces - Britain's allies. The intervention of the Fusiliers, under orders from their brigade commander, Brigadier Tom Brodie, escalated into a diplomatic incident and was reported in the British press at the time.
Things were different in South Korea.
While massacres by communist forces - there were trenches filled with hundreds of dead civilians after the North Korean army's retreat from Seoul - received widespread publicity, those committed by South Korean forces were hushed up. Many stories have emerged only in the past 10 years of liberal rule in the country.