Time for some innovation - Integrate the newly installed THAAD anti missile system sensors in South Korea to into the GMD system to provide launch end guidance as a start.  The Chinese are already PO'd about the capabilities in that regard, capitalize on it.  Move SBX back to it's original intended port in ADAK, build another few SBX platforms - one or two real, some fakes as asymmetrical decoys.  Put the South Koreans on notice - get busy moving Seoul south and the Chinese as well - prep yourself for a glass crater on your border.  Radioactive by the way.  Next time the North Koreans yank the collective chain with a sinking or artillery barrage, take out a port.  Make a point and prep the area for an invasion at the same time.