By Emily Bazelon, Phillip Carter, and Dahlia Lithwick

Every few months a new story of torture by American troops or agents emerges in the media. Usually it is misunderstood, spun for propaganda, or ignored altogether. Yet understanding U.S. interrogation practices is vitally important, now more than ever, because these events (and their coverage) have a decided impact on our national security. Whether through an account of a savage prisoner-killing in Afghanistan or a Quran being desecrated in Guantanamo Bay, the world sees and judges us based on these stories.

Many Americans feel uneasy about the idea of torturing prisoners; others accept that desperate times may call for desperate security measures. Either view leaves open hard questions. For those who are ready to countenance torture to prevent the detonation of a "ticking time bomb," who should be authorized to decide when that situation has arisen and how far interrogators should go? The number of official inquiries into whether the interrogation practices in Iraq, Afghanistan, and Guantanamo rise to the level of torture-as many as 10 to date-demonstrates the difficulty of determining who in the chain of command bears responsibility for tactics that exceed the military's traditional limits.

The very word "torture" encompasses too many possibilities. Is scaring a prisoner with a dog really torture in the first place or just a modified fraternity prank? Is hooding a terrorist all that bad? Without a larger context, it's impossible to know how to frame these issues. Which explains why the American public finds itself either "for" or "against" torturing alleged terrorists, without having developed nuanced ideas of what such positions mean. We are debating in black and white instead of recognizing shades of gray. And much of the official thinking has taken place behind closed doors, preventing public understanding of where the relevant government actors have drawn the lines and why.

This series provides the facts and law to illuminate and add depth to the torture debate-not to persuade you to support or oppose it, but to help you formulate your own views on where the acceptable boundaries may lie. We've tried to separate facts from analysis, using principally the primary documents made available through government reports, leaks, or Freedom of Information Act requests. The aim is to inform the national conversation about the way America acts in the war against terror.