The administration also claims that Kurnaz traveled to Pakistan with Selcuk Bilgin, a man who -- according to the tribunal that reviewed Kurnaz' detention -- later carried out a suicide bombing. Guilt by association again, but there's a larger flaw in the administration's case: Bilgin (according to German investigators) is very much alive, and therefore could not have carried out a suicide bombing.

Yet military tribunals are unconcerned with the niceties of evidence or proof, as demonstrated by a tribunal's finding that Kurnaz is indeed an enemy combatant. It relied on "classified material" to arrive at that conclusion. The perils of basing a loss of liberty on secret evidence became clear when Kurnaz' detention was reviewed by a federal judge.

[A] Federal District Court judge, Joyce Hens Green, in reviewing Mr. Kurnaz's case early this year, found that there was only a single document, called R-19, that incriminates Mr. Kurnaz as a member of Al Qaeda. About this material she concludes, "Not only is the document rife with hearsay and lacking in detailed support for its conclusions, but it is also in direct conflict with classified exculpatory documents."

The tribunal, it turns out, simply disregarded evidence that didn't fit its theory about Kurnaz' danger to the U.S.

Judge Green's summary of the classified file was briefly unclassified earlier this year and reported on by The Washington Post in March. It contained several intelligence reports that exonerated Mr. Kurnaz of the very charges the Guantánamo tribunal made against him.

The administration resists judicial review of detentions, claiming that its own tribunals are sufficient to provide due process. Never mind that our government is based on a separation of powers that allows one branch of government to provide a check against the excesses of another branch. The administration's desire to keep all the power to itself -- to decide itself who should be held indefinitely, with no review by an independent judiciary -- is contrary to the fundamental structure of our society. Kurnaz' case demonstrates the evil that inheres in allowing the administration that kind of unchecked power.