Do nuclear weapons offer coercive advantages in international crisis bargaining? Almost seventy years into the nuclear age, we still lack a complete answer to this question. While scholars have devoted significant attention to questions about nuclear deterrence, we know comparatively little about whether nuclear weapons can help compel states to change their behavior. This study argues that, despite their extraordinary power, nuclear weapons are uniquely poor instruments of compellence. Compellent threats are more likely to be effective under two conditions: first, if a challenger can credibly threaten to seize the item in dispute; and second, if enacting the threat would entail few costs to the challenger. Nuclear weapons, however, meet neither of these conditions. They are neither useful tools of conquest nor low-cost tools of punishment. Using a new dataset of more than 200 militarized compellent threats from 1918 to 2001, we find strong support for our theory: compellent threats from nuclear states are no more likely to succeed, even after accounting for possible selection effects in the data. While nuclear weapons may carry coercive weight as instruments of deterrence, it appears that these effects do not extend to compellence.