Tensions between the rival Koreas have escalated as North Korean leader Kim Jong Un flaunts his advancing nuclear and missile programme and engages in electronic and psychological warfare, including flying thousands of balloons to drop trash and anti-South Korean propaganda leaflets in the South. South Korea’s Joint Chiefs of Staff said North Korean operations to manipulate GPS signals were detected from around the western border city of Kaesong and the nearby city of Haeju on Friday and Saturday, and said the activities disrupted dozens of civilian aircraft and several vessels. While warning …