A no-win situation that the president must be seen to be winning

By M.S.

HOW serious is the terrorist threat that justifies the National Security Agency's surveillance of Americans? Edward Snowden, the NSA leaker, doesn't address this question; his point is that the American people should have the information they need to decide whether the threat merits the surveillance. Matthew Yglesias thinks the threat isn't very serious, and that counterterrorism efforts, including surveillance and airport security systems, should be subjected to a cost-benefits analysis. ("Approximately zero lives per year are saved by airport security measures," he writes, though he admits he could be wrong about this.)