South Korea urged North Korea not to halt development of a joint industrial zone Thursday, a day after the North threatened to shut their shared border because of escalating tensions. South Korea set up the sprawling complex in the North’s border city of Kaesong during reconciliation moves in recent years. But its future was thrown into doubt Wednesday when North Korea’s military said it would “restrict and cut off” cross-border routes from Dec. 1. Analysts said the threat appeared to be designed to humiliate South Korea — whose new government has vowed to get tough on the North — by hobbling the Kaesong project that has served as a beacon of hope for reconciliation. Full Story