At times like this, I find that sarcasm is the only defence. Any attempt to suppress the upwelling of it has me frothing at the mouth.
When some smooth idiot of a poltician advocates negotiations, remember:
this is a nation whose leader had people kidnapped to make him films, for goodness' sake!
The country also abducted Japanese to teach in their spy school. They then claimed 8 were dead, but that was a lie.
North Korea has abducted people from Lebanon, Romania, Yugoslavia and Thailand.
Personally, I think anyone who attempts to negotiate with them is several clowns short of a circus.
if you want to know who is at least partly to blame, thank our ally Pakistan:
"More recently, Pakistan has played a substantial role in the progress of North Korea's nuclear program. In the second half of the 1990s, Abdul Qadeer Khan, scientist and "father" of Pakistan's nuclear program, supplied uranium enrichment equipment and perhaps even warhead designs to North Korea, according to some news reports. Khan originally came to world attention for stealing centrifuge designs and equipment while working in the Netherlands in the 1970s. After returning to Pakistan, Khan used suppliers from around the world to build centrifuges capable of enriching uranium for Pakistan's bomb program. Those vendors and manufacturers became the foundation of an extensive and profitable black market run by Khan and others, which amassed hundreds of millions of dollars. U.S. intelligence agencies monitored Khan's network for years but did little to halt the traffic, so as not to compromise sources and methods or, later, jeopardize relations with Pakistan. Achieving short-term foreign policy goals took precedence over preventing widespread nuclear proliferation. 
Finally, in early 2004, Pakistan's President Gen. Pervez Musharraf placed Khan under house arrest but pardoned him soon after. Neither the United States nor the International Atomic Energy Agency (IAEA) was permitted to interrogate him. On February 4, 2004, Khan admitted on national television that he was responsible for widespread nuclear proliferation. Later news reports described how Pakistani centrifuges were transferred to North Korea in exchange for ballistic missile technology.  In 2003, New Yorker reporter Seymour Hersh wrote that U.S. intelligence agencies believed that Khan had made at least 13 trips to Pyongyang, the last in June 2002. "
Of course, you also need to thank Russia and China, who have supported and egged on North Korea since 1945. They continue to mainatain support for this barbarous regime for the obvious reasons.
See JOSHUAPUNDIT for more informed comment.
The [UK] Prime Minister has condemned North Korea's apparent first nuclear weapons test as a "completely irresponsible act".
Even Pyongyang's closest ally China expressed its "resolute opposition", calling the move "brazen".
So that's ok then. We can all relax about the Jack Torrance among nations.