Just 15 men remain at the prison, down from hundreds when it opened 23 years ago. But the costly operation could go on for years.

A three-judge appeals panel will decide whether the plea deal Khalid Shaikh Mohammed reached to avoid a death-penalty trial remains valid.

Justice Department lawyers are defending the defense secretary’s decision to back out of the agreement that avoided a death penalty trial, moving the question from military to civilian courts.

A court filing said the prisoner was at risk for abuse and might not be able to get adequate health care if transferred.

The three-judge decision appeared, at least for now, to put plea proceedings for Khalid Shaikh Mohammed and two others back on track to take place in early January at Guantánamo Bay.