When liberals put the case for civil liberties, they sometimes claim that obnoxious measures do not help the fight against terrorism anyway. The Economist is liberal but disagrees. We accept that letting secret policemen spy on citizens, detain them without trial and use torture to extract information makes it easier to foil terrorist plots. To eschew such tools is to fight terrorism with one hand tied behind your back. But that—with one hand tied behind their back—is precisely how democracies ought to fight terrorism.
Human rights are part of what it means to be civilised. Locking up suspected terrorists—and why not potential murderers, rapists and paedophiles, too?—before they commit crimes would probably make society safer. Dozens of plots may have been foiled and thousands of lives saved as a result of some of the unsavoury practices now being employed in the name of fighting terrorism. Dropping such practices in order to preserve freedom may cost many lives. So be it.