A startling equivalence marks the logic employed by those who would defend democratic life and governments from terrorism by resorting to torture, and those who justify terrorism itself as a defense against excessive governmental power. Torture by the counter-terrorist state is sometimes seen as a necessary and convenient way of combating the threat of terrorism, as if the great evil of terrorism cancels out the lesser evil of torture. After September 11, 2001, arguments in favor of official torture penetrated deep into parts of the legal bureaucracy, political establishment, and academic circles in the United States, just as torture had sometimes been favorably viewed in earlier counter-terrorist campaigns, such as in French Algeria, Northern Ireland, and the Israeli-occupied territories. Similarly, some terrorist groups and their supporters justify their violence by appealing to various rhetorical, ideological, and moral claims about the necessity of terrorism in struggles of various kinds against oppression, authoritarianism, occupation, or other forms of domination or hegemony.

The equivalent logic of terrorists and torturers is manifest in three key techniques of argumentation: first, a paradoxical appeal to the language of human rights to justify torture and terrorism; secondly, arguments about asymmetry of power necessitating resort to terrorism or torture; and thirdly, a series of strategies invoked to justify the use of the exceptional means (of torture or terrorism) to achieve just causes.