To which country do the Rodong-1 missiles bring the most threat?

North Korea continues to refuse more negotiations about their nuclear weapons and ballistic missile programs. Satellite photos indicate that North Korea appears to be preparing another test of its Rodong-1 missiles. With a range of 1,200 kilometers, the Rodong-1 can reach targets in Japan, which has caused Japan to spend billions of dollars on American missile defense systems. North Korea is thought to have 100-200 Rodong-1 missiles, which are liquid-fueled, clumsy to prepare for firing and based on World War Ⅱ German missile technology.