While visiting an ancient royal palace in Kaesong, north of the demilitarized zone separating the two Koreas, I was chatting to a pleasant young woman in uniform, who was my guide. For a few minutes, my government 'minder' was out of earshot, and the woman leaned forward, and asked: "Do you know this?" She then sweetly hummed 'Silent Night' in a low voice. I was electrified. This was clearly a statement of dissent, if humming can be called that, to the North Korean regime.