EVEN IF HE WAS SUPPOSED TO fly a plane into the White House on the evil morning of Sept. 11, as he testified in court Monday, Zacarias Moussaoui should not be executed. Even if he knew enough, sitting in jail on immigration charges, to have stopped the slaughter at the World Trade Center, at the Pentagon and in a Pennsylvania field, killing the 20th hijacker is actually a worse idea than executing most other murderers on death row.
Monday's dramatic testimony marked the first time Moussaoui has spoken publicly since that world-changing day when 19 hijackers used four planes to kill nearly 3,000 people in the worst attack on the continental United States. Hearing his voice was like picking a scab of a wound that will never heal. And it begs a series of what-ifs: What if the FBI had let its man in Minneapolis seek search warrants based on the French Muslim's curious desire for jumbo-jet training and his professed hatred for the U.S.? What if we could hear all of the witnesses testify, instead of suffering from their silence because a federal lawyer improperly coached many of them through their expected cross-examination?
The 19 hijackers are dead. But there is still Moussaoui. He knew. He helped. Shouldn't he die?
No, he should not. Many committed opponents of the death penalty want to carve out exceptions for mass murderers or those who attack or betray the nation writ large, such as Timothy McVeigh. But if you believe, as does this page, that the death penalty debases our society, the principle becomes all the more important when it is most tempting to ignore.
But for those who don't share that conviction, there are some more practical arguments.
Would-be suicide jihadists want to die in their struggle against us in the deluded belief that God will reward their murderous cowardice. Once they are in our custody, they lose the power to achieve that goal. Capital punishment gives them the martyrdom they crave, making them symbols of sacrifice to would-be followers rather than powerless, humiliated prisoners passing the decades alone and increasingly forgotten in a cell.
More important, if Moussaoui is indeed an important cog in a broad conspiracy, then he certainly has information that could potentially be useful both in further Sept. 11 investigations and in our fight against Al Qaeda, whether now or in 10 years. We may or may not get this information from him if he lives, although life in prison is a very long time. But we will certainly not get it from him if he dies.
And killing him would do nothing to stop future attacks or alleviate the loss of the past. That's the hard thing about the death penalty: The heart screams for retribution, but it is never enough. It is vengeance devoid of benefit.