North Korea Cranking It Up

Last year, when Psy was everywhere i turned doing his Gangham Style dance i did wonder why it was North Korea that was considered the bad guy but he has thankfully disappeared again and our attention is turned back to above the 38th parallel and Kim Jong Un.
At first glance it is difficult to understand why the North Koreans are threatening not only the most advanced military in the World but also one of the most keenest to use it. If North Korea attacked America, Kim Jong Un and his country would be obliterated so why tug on the tail of the tiger at all?
Over the last few decades, North Korea has found that if it throws a tantrum, it gets aid and as North Korea is a land of not much, it needs international aid.         
North Korea now though face the problem of stamping its feet so often and so loudly that nobody is taking much notice anymore so it has to make people take notice and its thinking is to crank up the rhetoric.
Coupled with a new, young leader keen to show that he is no pushover, North Korea could become more of a problem than we give it credit for.
In 2010, under Kim Jong Il, Pyongyang sank a South Korea ship killing 46 and shelled civilian and military building on the Yeonpyeong Island killing 4 South Koreans following US and South Korean war games so it has proven that it is willing to reach for the military if it deems necessary to bring the attention back to itself.  
The concern is that with tensions so high, events could quite easily spiral out of control and an escalation could easily follow something going off by accident or a misinterpretation or even a miscalculation and these things can spiral out of control.
What is also seemingly overlooked is that although there is plenty of bluster around North Korea's nuclear weapons, there is no proof that they have the ability to deliver a nuclear warhead to the coast of America but what they do have is thousands of ballistic missiles and a vast array of chemical and biological weapons that would inflict carnage on it's neighbours in the South and Japan in an initial onslaught.
It wouldn't survive long afterwards but it would go out with one almighty bang and take large swathes of its enemies with it.