can north korea be safe?

this problem exists for a long period.
these days, north korea announce that they want to test a long-rang missile, that can attack the region of usa directly.and also, these day, undated u2 spy plane has been deployed in osan air station. though an usa forces korea offical said that "this move is planned preivously, not related to the test of north korea.", no one will believe it.
these days, i've a nice experience with the experiment of implementing a compiler base on a simple programming language called c- defined by our teacher ms Li. to be confess, i didn't read any introduction about the tools containing lex and yacc. last friday afternoon is my quit right beginning with this discipline.but from the procudure of the experiment, i have to read a lot of imformation about these two tools. that 's really what your see is waht your learn.
it's too late, i need to go bed and have a sweet dream.