The decision undoes an attempt to wrap up more than two decades of military prosecution beset by legal and logistical troubles.

Federal judges ruled 2-1 that Defense Secretary Austin had legal authority to cancel the Guantánamo Bay plea deal for Khalid Sheikh Mohammed in the 9/11 case.

Khalid Sheikh Mohammed is accused of organizing the plot to crash hijacked airplanes into the World Trade Center and the Pentagon in 2001.