Advocates of humanitarian intervention often claim that 5,000 U.N. troops alone could have staved off the Rwandan genocide in 1994. But a more realistic appraisal suggests that an intervention of any size would have required much more time and logistical planning than most proponents care to admit. Given the genocide’s terrifying pace, even a major mission by the West could have saved only a fraction of the ultimate victims. Herewith a reassessment of the limits of intervention.