(CNN) Like all of President Donald Trump's enemies, Kim Jong Un now has a catchy nickname -- "Rocket Man." Trump will always be Trump, no matter international protocol or the gravity of a national security crisis. Yet mocking Kim, as Trump did on Sunday in a tweet, cannot disguise a sobering reality that the North Korean dictator is winning his race to twin a nuclear bomb and a long-range missile that could hit US soil. Meanwhile, White House aides who have said that diplomacy is the preferred US option are talking tough -- escalating their rhetoric as Trump debuts at the United Nations General Assembly. "If North Korea keeps on with this reckless behavior, if the United States has to defend itself or defend its allies in any way, North Korea will be destroyed," US envoy to the UN Nikki Haley said on CNN's "State of the Union" on Sunday. Despite using an Elton John hit to demean Kim, Trump, who critics say has worsened the crisis wi...