North Korean troops appear to have temporarily pulled back from the frontline in Russia after suffering heavy losses, a Ukrainian special forces commander has told Sky News. The commander, who goes by the codename "Puls", said Kim Jong Un's men were likely either learning lessons from mistakes made during their first, bloody clashes with Ukrainian soldiers, tending to their wounded or waiting for reinforcements. "I think they'll be back soon," he said, speaking at a secret base in northeastern Ukraine. Interviews with several Ukrainian troops reveal remarkable details about how the North Koreans have been fighting since they arrived on...