The attack on the Boston Marathon is a reminder of the adage that terror is theater. Yes, terror is horror. Yes, terror is murder. Yes, terror is reprehensible. But it is theater, too, played out on a grand stage before an audience of tens of millions. We sit riveted in front of the television or computer screen, demanding the latest updates.

We don't need to know who did it to understand the malevolent brilliance of the staging: an attack on the audience at a sporting event where the crowd is uncontrollable. Suddenly everyone is worried about which "soft" target will be next. (In Israel, everyone understands that shopping malls and night clubs are natural attractions for terrorism.)

The response to terror is also theater. This probably explains why so many observers criticized U.S. President Barack Obama when his initial statement, just hours after the attacks, omitted the word "terrorism." The president was displaying an understandable legalistic caution, but he missed the sense of occasion: Act 1, Scene 2, the leader of free world and the de facto commander in chief of the War on Terror takes the stage alone. His performance must be equal to the anxieties of his worried people. On Monday it wasn't; on Tuesday it was.