North Korean Missiles

The topic that I chose from class was North Korean Missiles. My research questions are:
1. Why is North Korea having these missiles so dangerous?
2. How did they get them?

I think that it is important to know why the country of North Korea itself is so dangerous because then I will know if them having the missiles is any more dangerous then any other country having them. Also, if I find out why the country is dangerous, then I may be able to tell more about what their intent is for the missiles that they now have. My second question is important because if North Korea has suddenly found a way to develop these missiles then there would be a problem of national security. However, there would be a larger problem if another country has developed them and was now giving them away. This question would also lead to more questions along the lines of "How are the missiles made?" and "Why does America not have them?"