So as president, would you do a preemptive strike on NK, using a Trident?  I don't think SK and Japan would be very happy with you, given that radioactive debris would rain on them.

If no preemptive strike, then a retaliatory strike?  That means a US territory or that of an ally would have to take the initial incoming hit.  This is what makes people living in Honolulu and west coast cities nervous.