Striking North Korea won't have Jong Un saying "my bad, I'll give up all my chemical, biological, nuclear weapons & behave now". It will slaughter innocent people, antagonise NK & prove the point of their anti-US "they want to kill us" propaganda & will p off Russia & China - the latter of whom has threatened to retaliate on NK's behalf. 
The best thing the US can do is bombard NK with free mobile phones & allow them access to free Wifi, so they can free themselves of their evil Dictators. Every North Korean who has escaped has been astounded at the lies their regime has told them, how much they're kept in the dark & how poor the conditions they live in actually are. Start a revolution not a war!