Since September 11, 2001, much has been said about the difficult balancing act between freedom and security, but few have made specific proposals for how to strike that balance. As the scandals over the abuse of Iraqi prisoners at Abu Ghraib and the "torture memos" written by legal officials in the Bush administration show, without clear rules in place, things can very easily go very wrong.With this challenge in mind, Philip Heymann and Juliette...