Rivalries Within North Korean Elite Led to Purge, South’s Spy Chief Says By CHOE SANG-HUN SEOUL, South Korea — South Korea’s intelligence chief said Monday that Jang Song-thaek, the uncle of the North Korean leader, Kim Jong-un, who was executed this month, apparently had not plotted a coup as Pyongyang had said, but had fallen victim to intrigue within the country’s elite over lucrative business deals, according to lawmakers in Seoul. Mr. Jang, 67, who was once believed to be the second most powerful man in North Korea, was executed on Dec. 12 on charges of plotting to overthrow his...