Anyone in SF who can actually afford to live in that Liberal Hell is barely sentient, anyhow, so it would be a twofer. Kim liquidates the Clinton/Obama foreign policy, forever, and we have every justification in vaporizing the Norks until they are no longer a threat, at least for the next 50 years...
Thermobarics, cluster bombs, dumb bombs, we don't even have to go nuclear. Let's see if the Air Farce can actually end a war without boots on the ground.
They won't hit SF in this fashion. City of seven hills. Center of SF near Market and Van Ness is a valley between hills. The blast effect would bounce off hills and be directed eastward towards Oakland and Berkeley (which is okay). All the U.S. military bases in the region disappeared over the last few decades including bases on Treasure Island, Alameda and Hunters Point, so minimal to no impact to military. SF isn't safe from the Russians or China, as they have dozens of powerful nukes aimed at the SF Bay Area for total annihilation. But NK with a single 20KT nuke will barely make an impact except for the financial sector (the Fed and stock exchanges in that valley), most of the city will survive.