Crazy dictator with a nuke, what could possibly go wrong? Except maybe we shouldn't push the panic button just yet. Kim Jong Un isn't crazy in the same sense that an ISIS suicide bomber is. This article http://www.nbcnews.com/news/world/north-korea-after-icbm-test-what-does-it-really-want-n779636 makes a good case for the logic of his behavior:
"...for all its apocalyptic bluster, the country's pursuit of a nuclear weapons program — including its first intercontinental ballistic missile launch Tuesday — is based on what it believes are a rational set of goals. The most important of these is self-preservation."
"They learned their lesson from Libya and Iraq that the sure-fire way to
prevent an attack is to have weapons of mass destruction, rather than
just bragging about it," said John Nilsson-Wright, a senior research
fellow at Chatham House, a London-based think tank."
"...developing an intercontinental ballistic missile "is a predictable
and rational step for North Korea's military programs," according to
Andrea Berger, a senior research associate at the Middlebury Institute of International Studies at Monterey, in California.
"Pyongyang believes that holding continental
U.S. targets at risk is essential for deterring the United States from
initiating regime change, or from joining a conflict that starts in
other ways," she said."
"...some experts, such as Nilsson-Wright, believe that "North Korea has called Trump's bluff."
He believes that, after the U.S. weighs the heavy casualties that would result, war is unlikely.
"....North Korea, he added, has "probably handled things in a way that's not
so much a miscalculation but a calculated cost-and-benefit analysis."
The primary goal for Kim Jong Un is preservation of his own hegemony and the Kim dynasty. As for the US, there are several choices, none of them good. A surgical strike to take out Kim Jong, or all out war, would endanger our allies S. Korea and Japan more than any other, and a retaliatory strike or an attempted one, on the US is all but inevitable. Kim Jong has stated that a negotiated end to his nuclear program is off the table. I believe that is true. The best choice for us is acceptance, because the ship has already sailed as far as preventing N. Korea from having nuclear weapons. What we will be dealing with is a cold war, mutually assured destruction. Not what we would prefer, but worked for half a century with Russia.