Since I was in basic training during the Cuban Missile Crisis and as a result have spent a fair amount of time reading the since declassified reports of that debacle, both on the Kennedy side and the Khruschev side, I can't disagree that it is a dangerous world. 

Whether it is the back-pack nukes that both the US and the USSR 'used to have' or the acknowledged weapons on various countries' submarines or missiles of today, or the  'Broken Arrow' accidents from Greenland to Spain, 'bad things' can and have happened.  

I have also received some military training on Nuclear warfare, to include target analysis of such things.  A North Korean hit on Seattle could very well provide a downwind hazard to Eugene at the right time of year.

Mount St. Helens ash hit Portland, after all.

These things exist and will continue to exist worldwide for decades to come. 

If the leader of North Korea uses one on Hawaii, do you think we will just ignore it and say 'Too bad"?  

I don't.