As a "maneuver," however unwitting, doubling had allowed the Nazi doctors to be murderers and decent family men at the same time. In similar fashion, doubling is likely the way the two Boston Marathon bombers were able to reconcile the absolute ordinariness of their day-to-day lives and ambitions with an otherwise unfathomable cruelty. Earlier, Arendt had explained evildoing with thoughtlessness or "banality." In the case of the two brothers in Boston, and also of certain other identifiable perpetrators of anti-American terrorism, a corollary explanation would seem to lie in doubling.
As with the Nazi doctors and the Jews, it is plausible that they, too, regarded the indiscriminate mass killing of "others" as a pleasing and possibly even sacred form of healing. Now, with nameless "Americans" as their target, a healing-killing paradox could have been crucial to their plainly murderous calculations.
There can be, we should all now understand, a verifiably abnormal side to normalcy. This is not an oxymoron. For the future, in thinking about how best to protect ourselves from terror-crimes, we would be well-advised not to think of our prospective tormentors in stiffly caricatural or rigidly polar terms. Rather than limit our attention to only those who are manifestly and conspicuously psychopathic, we should proceed with a more deliberately nuanced and aptly subtle sort of reasoning.
It is improbable that the two Boston Marathon brothers had merely feigned normalcy in order to void suspicion. Almost certainly, they were normal young men, but, in this case, also endowed with a finely-honed capacity for doubling. Determined to wreak "revenge" upon America, a nation that had become, in their own too-willing minds, the present-day equivalent of "a gangrenous appendix in the body of humankind," they eagerly turned to mass violence against the "guilty."
To be sure, doubling was not the only reason the Tsarnaev brothers and certain others were able to do what they did. It will assuredly turn out that captivating elements of "groupthink," especially a desperate need to belong, were also a dominant influence. But whatever types of explanation ultimately emerge as most compelling and persuasive, we may still have to accept that these murderers, in the fashion of other terrorists, were clinically normal.
With such a deliberately informed acceptance, our national counterterrorism strategy could be substantially improved and enhanced. In time, this sort of acceptance, however grudging or disturbing, could prove indispensable to warding off certain higher-order or mass-destruction terror attacks against the United States. We ought, therefore, to take it very seriously, at complementary intellectual and policy levels.
Louis Rene Beres is a professor of International Law at Purdue University. Born in Zurich, Switzerland at the end of World War II, he is the author of many major books and articles dealing with world politics, law, literature, and philosophy.