Mark Osiel has written five books on the law of war, most recently Trying Tyrants: Making Sense of Mass Atrocity (Cambridge University Press, 2008) and Mass Atrocity, Ordinary Evil, and Hannah Arendt: Criminal Consciousness in Argentina's Dirty War (2002). He has lectured at the International Criminal Tribunal for the former Yugoslavia and advised on the prosecution of General Augusto Pinochet and the perpetrators of the Rwandan genocide. He regularly consults to international organizations and governments in post-conflict societies on issues of transitional justice. Osiel has been a Visiting