Congress and political opposition thwarted that effort. Now the case is back at the Guantánamo war court, where the Pentagon uses some Justice Department lawyers and blends both military and civilian practice.

Different courts

• UK vs. CIA

In the Masri case, the British government imposed two conditions on the extradition of the five accused terrorists to U.S. soil — no execution if convicted and no military prosecution, then turned him and four other men over to U.S. jurisdiction. Mohammed came to military custody from the CIA, which still controls classifications in the 9/11 case, notably the details of his black site detentions and interrogations, including 183 rounds of waterboarding.

• Federal judge vs. 40-second delay

Spectators walked in off the street, went through a metal detector and sat in court for Masri’s 30-minute arraignment. Sketch artists sat in the jury box, close enough to illustrate that Masri’s arms end in stumps, he says from an explosion in the 1980s while he fought the Soviet invasions of Afghanistan. For Mohammed’s arraignment, the Pentagon vetted spectators — Sept. 11 victims, legal observers, reporters, who in Cuba watched the 13-hour 9/11 proceedings through a soundproofed window behind the court. Sound comes in a 40-second sound delay, time enough for a censor to muffle with white noise button sensitive information. The sketch artist was sequestered in back too. A security officer inspected her drawings before the public could see them.

• Release vs. indefinite detention

If a civilian jury acquits Masri, he goes free. The United States might seek to deport him back to his native Egypt or negotiate his return to Britain, where his family lives. Acquittal by military commission does not automatically guarantee you get out of Guantánamo. Obama detention doctrine says the Pentagon can keep a foreigner indefinitely as a captive of the war on terror — unless a federal court orders the government to let the man go.

• Settled system versus expeditionary justice

There’s no question that Masri is entitled to the protections of the U.S. Constitution at his trial. Not so at the U.S. military court in Cuba. Defense lawyers have asked the Army colonel presiding at the 9/11 trial to rule on whether military commissions are governed by the U.S. Constitution. The prosecutors want that issue decided later.