Most certainly one shot off by the US would make russia feel free to flatten Berlin in a similar fashion. Bad Vlad has been champing at the bit to do that for a while, he wants the kiev Jewel for the crown and the next biggest military power in Europe is Germany.
China gets a free pop at taiwan, again, something they've been shaping their military for for a while, it's not like the US has the stones to fire nukes at another nuclear power