But the emotion of watching the Koreas march under the same flag moved some spectators. More than 100 South Koreans watching on a live stream on a screen in central Seoul applauded and cheered while watching that moment.

Kim Tae-yoon, 21, a media studies student from Cheonan, said that he had been dubious about the North Koreans participating in the Games.

“I wondered whether any of our efforts would be a step towards unification when we could very well just be used for North Korean propaganda,” Mr. Kim said. “But the two Koreas marching together looked good. I hope that the Pyeongchang Olympics will be remembered as one where we showed the world that we communicated well with North Korea.”

Perhaps the most stirring moment of the evening came when the penultimate torch bearers were revealed as Chung Su-hyon, a North Korean player for the unified Korean hockey team, and Park Jong-ah, a South Korean player. The pair carried the torch up the final flight of steps and handed it off to Yuna Kim, the profoundly popular South Korean figure skater who won the gold medal in 2010 and the silver in 2014.

This event was not the first time that athletes from North and South Korea have marched together under one flag. They did so in 2000 at the Sydney Olympics in Australia, in 2004 in Athens, and in 2006 in Torino, Italy.

But by doing so in South Korea — and in Gangwon Province, where North Korea is visible from the peaks of the ski slopes — the symbolism this time was particularly striking. It also provided a stark contrast to the 1988 Summer Olympic Games in Seoul, where the North Koreans did not compete after organizing a terrorist attack in which spies blew up a South Korean airliner 10 months before the Games, killing everyone on board.