North Korea confirmed the launch of four missiles this week, which involved an upgraded long-range cruise missile system and a surface-to-surface tactical guided missile, state-run media reported on Friday. Two long-range cruise missiles were launched over the East Sea of Korea—also known as the Sea of Japan—on Tuesday, hitting a target island 1,800 kilometers (1,118 miles) away, state media Korean Central News Agency (KCNA) said in its report. KCNA also noted that Pyongyang launched two tactical guided missiles on Thursday to assess the “explosive power of the conventional warhead” of a tactical guided missile. South Korea’s Joint Chiefs of Staff earlier reported that two ballistic missiles were launched from Pyongyang’s Hamhung city on Thursday and traveled about 190 kilometers (118 miles) to a maximum altitude of 20 kilometers (12 miles). It also detected the two cruise missiles launched off the east coast of Korea on Tuesday. North Korean leader Kim …