GUANTANAMO BAY NAVAL BASE, Cuba — The self-styled terrorist mastermind of Sept. 11 wore a camouflage vest for the first time Wednesday at his military war crimes tribunal, a clothing choice previously denied because of fears it might disrupt the court.

Khalid Sheikh Mohammed, who has told authorities he was behind the hijacking plot, wore the woodland-style camouflage vest with a white tunic and turban at a pretrial hearing at the US base in Guantanamo, Cuba.