There was another missile crisis in 1962 when the Soviet Union was constructing missile launch sites in Cuba and bringing in missiles that could easily reach the U.S. 90 miles away.  President Kennedy ended that in October 1962 by ordering a naval blockade of Cuba.  Blockades are considered acts of war, so Kennedy called it a “quarantine.”  It worked.  Soviet ships heading to Cuba with missiles turned back to Russia and missiles already in Cuba were removed.  North Korea has shown that sanctions do not work.  A quarantine of North Korea just might do it.  Nothing in and nothing out by sea.   Yes, the poor people of North Korea will suffer, but perhaps no more than they have suffered since the Communists seized power in the 1940s.  And yes, a sea quarantine will place a great burden on China and Russia that border NK, but that should not matter because they created this monster.  It just might be enough to get China and Russia to cure NK's madness.