The government will have to choose between vigorous prosecution and revealing classified sources and methods.
By JOHN YOO'This is a prosecutorial decision as well as a national security decision," President Barack Obama said last week about the attorney general's announcement that Khalid Sheikh Mohammed and other al Qaeda operatives will be put on trial in New York City federal court.
No, it is not. It is a presidential decision—one about the hard, ever-present trade-off between civil liberties and national security.
Trying KSM in civilian court will be an intelligence bonanza for al Qaeda and the hostile nations that will view the U.S. intelligence methods and sources that such a trial will reveal. The proceedings will tie up judges for years on issues best left to the president and Congress.
Whether a jury ultimately convicts KSM and his fellows, or sentences them to death, is beside the point. The treatment of the 9/11 attacks as a criminal matter rather than as an act of war will cripple American efforts to fight terrorism. It is in effect a declaration that this nation is no longer at war.
KSM is the self-proclaimed mastermind of the 9/11 attacks on the World Trade Center and the Pentagon—and a "terrorist entrepreneur," according to the 9/11 Commission report. He was the brains behind a succession of operations against the U.S., including the 1996 "Bojinka plot" to crash jetliners into American cities. Together with Osama bin Laden, he selected the 9/11 terrorists, arranged their financing and training, and ran the whole operation from abroad.
After the U.S. invasion of Afghanistan KSM eventually became bin Laden's operations chief. American and Pakistani intelligence forces captured him on March 1, 2003, in Rawalpindi, Pakistan.
Now, however, KSM and his co-defendants will enjoy the benefits and rights that the Constitution accords to citizens and resident aliens—including the right to demand that the government produce in open court all of the information that it has on them, and how it got it.
Prosecutors will be forced to reveal U.S. intelligence on KSM, the methods and sources for acquiring its information, and his relationships to fellow al Qaeda operatives. The information will enable al Qaeda to drop plans and personnel whose cover is blown. It will enable it to detect our means of intelligence-gathering, and to push forward into areas we know nothing about.
This is not hypothetical, as former federal prosecutor Andrew McCarthy has explained. During the 1993 World Trade Center bombing trial of Sheikh Omar Abdel Rahman (aka the "blind Sheikh"), standard criminal trial rules required the government to turn over to the defendants a list of 200 possible co-conspirators.
In essence, this list was a sketch of American intelligence on al Qaeda. According to Mr. McCarthy, who tried the case, it was delivered to bin Laden in Sudan on a silver platter within days of its production as a court exhibit.
Bin Laden, who was on the list, could immediately see who was compromised. He also could start figuring out how American intelligence had learned its information and anticipate what our future moves were likely to be.
Even more harmful to our national security will be the effect a civilian trial of KSM will have on the future conduct of intelligence officers and military personnel. Will they have to read al Qaeda terrorists their Miranda rights? Will they have to secure the "crime scene" under battlefield conditions? Will they have to take statements from nearby "witnesses"? Will they have to gather evidence and secure its chain of custody for transport all the way back to New York? All of this while intelligence officers and soldiers operate in a war zone, trying to stay alive, and working to complete their mission and get out without casualties.
The Obama administration has rejected the tool designed to solve this tension between civilian trials and the demands of intelligence and military operations. In 2001, President George W. Bush established military commissions, which have a long history that includes World War II, the Civil War and the Revolutionary War. The lawyers in the Bush administration—I was one—understood that military commissions could guarantee a fair trial while protecting national security secrets from excessive exposure.
The Supreme Court has upheld the use of commissions for war crimes. The procedures for these commissions received the approval of Congress in 2006 and 2009.
Stranger yet, the Obama administration declared last week that it would use these military commissions to try five other al Qaeda operatives held at Guantanamo Bay, including Abu Rahim al-Nashiri, the alleged planner of the 2000 bombing of the USS Cole in Yemen. It should make no difference that this second group attacked a military target overseas. If anything, the deliberate attack on purely civilian targets in New York City represents the greater war crime.
For a preview of the KSM trial, look at what happened in the case of Zacarias Moussaoui, the so-called 20th hijacker who was arrested in the U.S. just before 9/11. His trial never made it to a jury. Moussaoui's lawyers tied the court up in knots.
All they had to do was demand that the government hand over all its intelligence on him. The case became a four-year circus, giving Moussaoui a platform to air his anti-American tirades. The only reason the trial ended was because, at the last minute, Moussaoui decided to plead guilty. That plea relieved the government of the choice between allowing a fishing expedition into its intelligence files or dismissing the charges.
KSM's lawyers will not save the government from itself. Instead they will press hard to reveal intelligence secrets in open court. Our intelligence agents and soldiers will be the ones to suffer.
Mr. Yoo is a law professor at the University of California, Berkeley. He was an official in the Justice Department from 2001-03 and is a visiting scholar at the American Enterprise Institute.