My Times colleague Mark Mazzetti has a new book out that is getting a lot of attention, including some cinematic excerpts published in The Times, here and here. “The Way of the Knife” recounts the recent transformation of the Central Intelligence Agency from a traditional spying shop into more of a man-hunting paramilitary — custodian of lethal drones, sponsor of dark ops, employer of secret armies and shady contractors.

As an assassination bureau, the C.I.A. has had some spectacular successes. (The Navy Seal raid that killed Osama bin Laden was led by the C.I.A.) It has also come in for some fierce criticism from those who are uncomfortable with assassination in general, with the eerily impersonal methods of remote killing, with the civilian casualties, or with the timid oversight of an agency licensed to kill. And of course the demand for operational intelligence to aid these manhunts drove the C.I.A. into the practice of torture and rendition.

But Mazzetti’s important thought is not that war is a dirty business; it is that by turning our premier intelligence agency into a killing machine, we may have paid a price in national vigilance.

Alone among the many U.S. intelligence outfits (the number has grown to 16 or 17 depending on how you count) the C.I.A. has the job of supplying the president with the deep strategic intelligence that anticipates dangers and shapes American policy. The agency has always housed both covert operations and the more traditional gathering and analysis of information — “cowboys and eggheads,” as one agency-watcher put it. The worry is that the eggheads have become so caught up in serving the cowboys tactical intelligence about high-profile assassination targets that they have less bandwidth to devote to longer-term threats.