If you served there then you should be aware that any pre-emptive strike we make will result in hundreds of thousands if not millions of innocent people dying, not to mention the poor shlubs in North Korea that have absolutely no say in how they live or what their gov't does.
North Korea does not and will not have the capability to "destroy us". Also, their wish is to stay viable and they know any attack on us will result in their utter destruction. They want the ability to harm us to cause us to not attack them.