I think that the best thing for civil liberties in America is that we've gone over 3 years without another 9/11 style attack.
In one sense this is undeniably true—the next attack will certainly cause further encroachments on our constitutional liberties (let alone the liberty of those who are slaughtered), and this is an excellent reason to be worried. But this logic, can be—and already has been—used to justify any number of government activities that not only harm civil liberties, but very arguably make it more difficult to prosecute the war on terror. One of the most infuriating things about Jane Mayer's must-read New Yorker article on extraordinary rendition is how the practice has crippled a number of prosecutions against, um, terrorists, in addition to producing a bunch of—surprise!—utterly useless and misleading confessions and intelligence information.
If civil liberties and national security were a zero-sum game—and this is not (as far as I can tell) what Reynolds believes, but it is within logical spitting distance of his sentence—then totalitarianism would be the safest form of government. It's not.