The Supreme Court's decision yesterday in Hamdan v. Rumsfeld, holding that the Guantanamo Bay military commission trials were unlawful by design, is by any standard a blockbuster. In a solid 5-3 majority opinion written by Justice John Paul Stevens, the Court ruled that the commissions violate the Uniform Code of Military Justice and the Geneva Conventions. To the prevailing post-9/11 mantra of Inter arma silent leges ("laws fall silent in times of war"), the Court, speaking in the voice of its sole remaining military veteran, issued a clear response: Not so fast.