I’m coming a bit late to this debate, but the Ahmed Ghailani debacle should be a wakeup call. In all but the simplest circumstances, it is extraordinarily difficult to conduct a proper civilian trial (in an American court with American rules) of a terrorist detainee captured overseas.

Much of the debate over terrorist trials has occurred at the theoretical level, as abstract ideals are tossed around without consideration of on-the-ground realities. Yet I was there, on the ground, running detainee operations for an armored cavalry squadron during the Iraq Surge. As a judge advocate, I was responsible for ensuring that each of our detainees was sent to holding facilities with the best evidence “packet” possible. I was responsible for doing what I could to provide additional supporting evidence, when possible. As a soldier and staff officer, I also had a grasp on the overall pace of operations, the challenges our guys faced in the field, and the horrific dangers at the height of our battle with al-Qaeda.

Is it the position of the attorney general that we should divert combat resources to create “CSI Kandahar” or “CSI Diyala,” so that terrorist detainees caught on the battlefield are treated with the same kind of forensic care as a domestic murder suspect? Should significant resources in infantry and armor be diverted from raids and area security to set up the crime-scene tape, dust for fingerprints, and canvass witnesses? To be clear, we certainly do what we can on the scene after bombings or other terrorist attacks, but the difficult elements of “real” police work — chasing down leads, interviewing and re-interviewing witnesses, repeating searches, surveying neighborhoods — are often not only impossible but suicidal in locations with live insurgencies.

So we did the best we could, and it was pretty darn good. But would our evidence “packets” have secured convictions in the Southern District of Manhattan? When I was in Iraq, we did not have a single M.P. (military police) on our base. Our work was done with cavalry scouts and armor officers, and they did a magnificent job and took great care in their work. But they’re not detectives, there were no Miranda warnings, and they cannot be held to that standard. It’s absurd. They’re war-fighters, not cops.

I vividly remember the day I learned that lesson. It was early in the deployment, and I had a lot to learn. We’d brought in a few detainees, and I was surveying the evidence packets. I approached the troop’s First Sergeant (most senior noncommissioned officer) and said, “First Sergeant, do you think we can get some more stuff on these guys? Could we go out and interview some additional witnesses? I’d like better Iraqi sworn statements.”

He gave me a look that I can best describe as respectful incredulity, and said: “Sir, we grabbed those guys after a troop-level raid in a hostile zone after riding over and through a known IED ambush. That operation took weeks to prepare, all of my guys risked their lives, and we were lucky enough to pull it off without anyone dying. You’re saying you want us to stop our other operations to plan another raid to maybe find one or two more people to give sworn testimony? People who won’t live another day in that village if they’re seen talking to us?”

I felt like an idiot for asking the question. I felt even sillier as I saw and experienced more and more of the world “outside the wire.” We can obtain considerable amounts of evidence, but real police work? In combat? That can be a life-threatening impossibility.

— David French is senior counsel for the Alliance Defense Fund Center for Academic Freedom.