INTRODUCTION   The American response to 9/11 has been much criticized around the world but not always carefully understood in the context of the United States’ unique legal and political culture. The American approach, especially in the three years after 9/11, was dominated by an aggressive assertion of executive power and by conduct that was supported by dubious claims of legality. The most infamous conduct was directed at non–American citizens outside the United States. It included detentions without trial at Guantanamo Bay and elsewhere, torture and abuse at Abu Ghraib and elsewhere, and increased use of extraordinary renditions to countries with poor human rights records. Some of the extralegal activity, such as the Presidential designation and military detention of Yaser Hamdi and Jose Padilla as enemy combatants and the illegal domestic spying of the National Security Agency (NSA), was directed at American citizens.