President Donald Trump warned North Korean leader Kim Jong Un on Tuesday that he has a nuclear "button" on his desk at all times and boasted that the US has "much bigger & more powerful" nuclear weapons -- a stunning threat that has once again raised questions over what it takes to actually launch a nuclear warhead.


원문출처 : http://www.cnn.com/2018/01/03/politics/trump-nuclear-football-explainer/index.html