Seems a sub would have a difficult time 'getting away' unnoticed after that type of launch.
The sub that sank the Korean Destroyer got away and Obama did nothing. He is covering this up. We are at severe risk. Obama is canceling his trip and heading home to manage the coverup.
That is what I was thinking. Prepositioned (by a sub) in a tethered silo anchored to the sea floor. Remote control blows the silo, missile breaks the surface, booster ignites, no sub to track. Show of force with no assets at risk.