When Attorney General Eric Holder announced last fall that he planned to try Khalid Sheikh Mohammed in a civilian court in New York, he was met with a firestorm of abuse. Despite the fact that hundreds of terror suspects have been tried and convicted in U.S. courts, the administration’s Republican opponents spun out a thousand reasons for treating Mohammed differently: His trial would create a target in New York City that would cost millions of dollars for security measures; he would use the proceedings to spread jihadist propaganda; he shouldn’t be entitled to the constitutional rights and protections afforded U.S. citizens. In short, KSM became the poster boy for the man too dangerous for the law. In March, the White House indicated that a decision on Mohammed’s trial was just weeks away. Months later, the administration is still mulling.

But instead of subjecting the so-called “worst of the worst” to a military tribunal, this past week the Obama administration fired up the tribunal system to try Omar Khadr, a child soldier. Khadr’s defense counsel, Jon Jackson, collapsed Thursday while questioning a witness and was airlifted back to the United States for treatment. There will be at least a 30-day delay in the proceedings. Maybe we can use this small break to look again at what Guantanamo has become and to acknowledge that Omar Khadr represents everything we shouldn’t be trying before a secretive military commission.

At 23, Khadr is the youngest detainee of the 176 remaining prisoners at Guantanamo Bay. He’s been there for eight years—one-third of his life. Born in Toronto, he is the only Westerner there. Khadr is charged with being an “unlawful enemy combatant” (later changed to “unprivileged enemy belligerent”) for allegedly throwing the grenade that killed Special Forces Sgt. Christopher Speer in Afghanistan in July 2002. Khadr was 15 at the time.

As a U.N. envoy who condemned the trial this week noted, no child has been prosecuted for a war crime since World War II. Under international law, children captured in combat are to be treated as victims, not soldiers, and their captors are meant to rehabilitate and repatriate them. There’s also a question as to why someone who allegedly committed acts of war against a military invader has been classified as a war criminal and terrorist. Finally, there’s the question of physical abuse: Khadr’s attorneys say the prosecutors have relied on confessions extracted after Khadr was coerced, abused, and threatened with gang rape by military interrogators. Last week, the military judge in the case ruled that Khadr’s statements were admissible, and they make up the bulk of the evidence against him.

In short, Khadr’s trial forces us to revisit the long and disappointing history of President Bush’s military commissions, the demands of international law, the terrible abuse of prisoners held by the United States—everything we want to forget about our worst legal missteps in the wake of 9/11.

Nobody disputes that there should be consequences for a teenager who throws a grenade on a battlefield. The question is whether a lifetime in prison, after a third of a lifetime at Gitmo, is proper, and whether the procedures that have been set up at Gitmo are fair: child soldier, torture, plus eight years of justice delayed. It’s why ACLU staff attorney Ben Wizner describes the case as “the perfect storm of what’s wrong with the military commission system.”

In 2005 the Bush administration decided to press forward with Khadr’s case because it felt it would be “easy” to prove. Last November, President Obama—who campaigned against the use of military commissions and promised in January 2009 to shut down Guantanamo—opted to put Khadr on trial, evidently to showcase the new and (slightly) improved military justice system that refined some but not all aspects of the original commissions. (The trials still allow hearsay testimony, for example.) How the commissions are to be shown to their best advantage by the trial and conviction of a marginal fighter who was dragged by his father into jihad, then possibly dragged by Americans into confessing, is unclear. If the point of this first trial of the Obama administration was to highlight evenhanded American justice, then is not the way to do it. It’s still beating up on a Canadian teenager—and the only reason he’s not a teenager anymore is that he’s been in custody for eight years.

The trial may not be getting much coverage in the U.S. media, but the foreign media have followed every motion and argument. For them, Guantanamo Bay is as much a stain on Obama’s foreign policy as it was on Bush’s. The trials of a child soldier and Osama Bin Laden’s cook are as riveting as the O.J. Simpson trial was for us. For most Americans, however, the trial of Omar Khadr has the vague sense of irrelevance, much like Guantanamo itself. What happens at Gitmo stays at Gitmo, and thank goodness we don’t have to think about it anymore.

So we will continue to use arguments about key players in the 9/11 attacks to shore up a system that has only ever been used against the cannon fodder. We like the idea of Gitmo; we just don’t care to hear about what happens there. In the eight years since we first invented the military commissions system at Guantanamo, only four terrorists have been convicted (two in trials), and two are now free men. The sad coda to the whole U.S. misadventure at Guantanamo is that we built a prison there for the people who most terrify us and have used it to go after people who didn’t much matter. We built it to hold people too dangerous to be brought stateside, then used it to warehouse people too embarrassing to let go.

The whole object of Guantanamo was to create a legal black hole, a place where we could make up the law as we went along. But that doesn’t quite capture the secondary tragedy of the place: Over time, it’s also become a memory hole, a place into which America has been allowed to banish all the evidence of a lawless, embarrassing, hysterical past.

A version of this piece appears in this week’s Newsweek. Like Slate on Facebook. Follow us on Twitter.