The Justice Department has prosecuted more than 500 terrorism defendants since 9/11. On its face, that statistic seems to show the federal government is doing its level best to keep us safe. But The Terror Factory: Inside the FBI's Manufactured War on Terrorism, a new book by investigative journalist Trevor Aaronson, describes an agency caught in a law-enforcement echo chamber.

The FBI prioritizes lone wolves—individuals not officially affiliated with a terrorist organization, but inspired to violence—finding many through sting operations that target troubled and easily influenced men. Results outlined in this exquisitely researched book are dismaying. 

According to Aaronson, many of those prosecuted for terrorism—particularly those caught through sting operations using informants—are more bumbling shit-talkers than actual threats. Some have histories of mental illness, others are simply fools or losers who talk a big game to impress a new friend—to their great misfortune, an FBI informant. Left to their own devices, Aaronson argues, many suspects would have neither the means nor the abilities to carry out plans of any kind. This includes Portland's Christmas tree bomber, Mohamed Osman Mohamud, the subject of a chapter excerpted in WW last week.

In the various and superbly detailed cases outlined in Aaronson's book, the FBI and its informants provide these suspects with weapons, equipment, know-how and money to carry out their sometimes feeble plans. In many cases, the accused are so buffoonish that, rather than being revolted by their involvement in terrorist schemes, one pities them.

Aaronson's book is not without flaws. Overall, he moves the reader through the plots quickly and smoothly. But at times the writing defaults to a newspaper style that weighs heavy in the longer format of a book. At times his style seems ticky. He has an odd habit of describing agents' and informants' hairstyles. Though it works as an outrage piece for civil libertarians, Aaronson's book also functions as a broader warning: Investigators focused on stings might not recognize new and different threats. When you're a hammer, the saying goes, everything looks like a nail. 

GO: Trevor Aaronson will read at Powell's City of Books, 1005 W Burnside St., on Monday, Jan. 21. 7:30 pm. Free.