Japan calls NK missile 'most grave threat ever'
(CNN)With its fourth missile test in four days, North Korea issued a stark reminder to the United States that its weapons program isn't going away.
North Korea has long maintained it wants nuclear weapons and long-range missiles in order to deter the United States from attempting to overthrow the regime of Kim Jong Un.
Pyongyang looks at states like Iraq -- where former dictator Saddam Hussein was overthrown by the United States, and Libya -- the country's late leader, Moammar Gaddafi, gave up his nuclear ambitions for sanctions relief and aid, only to be toppled and killed after the US intervened in the country's civil unrest -- and believes that only being able to threaten the US homeland with a retaliatory nuclear strike can stop American military intervention.
Many experts believe North Korea would not use the weapons first. Kim Jong Un values his regime's survival above all else and knows the use of a nuclear weapon would start a war he could not win, analysts say.