It is amazing the response that North Korea is able to achieve from the world just by making threats. It is a very low cost investment to a huge result. Has the country been watching "The Mouse that Roared"? over and over these past 60 years? If you have not seen it perhaps it is time: http://www.youtube.com/.... If you missed the original and its brilliant plot with Peter Sellers and Jean Seberg, please review. A tiny country without resources threatens the powerful world nations so as to receive a kind of Marshall Plan Europe received after WWII.
Combine this with the fact that American troops used more Napalm on North Korea than was used in the entire combined theaters of war in WWII (see the new book by Robert Neer at http://www.barnesandnoble.com/...), and you might have "battered child syndrome" joined with megalomania.
On the other hand, consider that other Asian nations have closed their borders and thus been quite attractive to the West. The idea of the closed exotic other is so beguiling to Westerners that many were led to their deaths trying to enter the forbidden country of Tibet in the 18th, 19th and early 20th centuries. Japan closed her borders from the 16th to the 19th centuries. Thus North Korea's behavior is not new or unique.