By putting on hold military commissions to try terrorists for war crimes, five Supreme Court justices have made the legal system part of the problem, rather than part of the solution to the challenges of the war on terrorism. They tossed aside centuries of American history, judicial decisions of long standing, and a December 2005 law ordering them not to interfere with the military trials.

Visiting Scholar John Yoo

As commander in chief, President Bush has the authority to decide on wartime tactics and strategies. Presidents Washington, Jackson, Lincoln and FDR settled on military commissions, sometimes with congressional approval and sometimes without, as the best tool to punish and deter enemy war crimes. Bush used them to solve a difficult tension: how to try terrorists fairly without blowing intelligence sources and methods.

The circus that was the trial of Zacarias Moussaoui shows the dangers in trying to use normal courtroom rules to prosecute terrorists intent on harming the USA. Bush's decision was supported by Congress, which authorized the president to use force in response to the Sept. 11 attacks. Earlier, Congress had recognized commissions in the Uniform Code of Military Justice, and last year it created an appeals process for them.

What the justices did would have been unthinkable in prior military conflicts: Judicial intervention in the decisions of the president and Congress on how best to wage war. They replaced his wartime judgment and Congress' support with their own speculation that open trials would not run intelligence risks. Their decision to impose specific rules and override political judgments about military necessity mistakes war--inherently unpredictable, and where our government must act quickly and sometimes secretly to protect national security--for the familiarity of the criminal justice system.

Two years ago, the same justices declared they would review the military's detention of terrorists at Guantanamo Bay. Congress and the president expended time and energy to overrule them. Hamdan will force our elected leaders to go through the same exercise again, effort better spent preventing the next terrorist attack.

John Yoo is a visiting scholar at AEI.