Al Qaeda's Death Sentence
One consequence of Moussaoui's sentence to life imprisonment rather than death is that when we catch bin Laden, Zarqawi and their rest of the AQ leadership, they'll be killed while resisting arrest.
Our governments cannot tolerate the smallest risk that the al Qaeda leadership gets life sentences. They'd remain an inspiration for terror with their lawyers broadcasting to the faithful, and we'd have to endure terror attacks and kidnappings designed to spring them. So life sentences would condemn thousands of our own citizens to death.
When the task force finds these folks in their spider holes - as they will - they'll chuck in a grenade then collect a few body parts for DNA confirmation. Game over.