ALONG THE DEMILITARIZED ZONE, South Korea—Lee Jae-hyeong brought his two children here to help them come to grips with the painful history of the Korean Peninsula, represented today by military checkpoints, heavy armaments, layers of barbed wire and a wasteland that has split North from South since 1953.

“I brought my kids here to think about the division of the nation,” he said. Instead, he lamented, “the kids are more focused on Pokémon.”

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