Yet that very shrinkage of the power to devastate is precisely what makes this nuclear weapon potentially the most dangerous ever manufactured. Fulfilling the Trump administration’s quest for nuclear-war-fighting “flexibility,” it isn’t designed as a deterrent against another country launching its nukes; it’s designed to be used. This is the weapon that could make the previously “unthinkable” thinkable.
Source: Doomsday Redux: the Most Dangerous Weapon Ever Rolls Off the Nuclear Assembly Line