well I dont see the USA ever useing Nukes on them. even if they did launch one themselves ( North K ) .. The US has other weapons that are just as destructive at this point.
Not sure if this makes any sense, but, they did put a Satellite in space. Im no expert , but why cant they just put a bomb on that and throw it from space ?
maybe its more technical then that. Recently the North K Satellite did pass over the east cost of the US.. If they can get a Satellite in space, that means they can at least reach California .