Is there a strategic case for the United States to sustain or expand its efforts to eavesdrop on German intelligence targets? Over the past week, German politicians and the media have grappled with claims that the U.S. National Security Agency listened to Chancellor Angela Merkel’s cellphone calls. For many commentators and the chancellor herself, this is by definition a huge breach of trust between allies. For more cynical observers, there is no serious cause for outrage. All states, they smirk, spy on one another.

Both the moralists and the cynics have solid arguments. But both also miss a simple point about Germany’s inherent value as a target for both American and non-American spies. There is a long history of espionage in Germany. Yet, whereas the main goal for Western spooks in Berlin during the Cold War was to assess the Soviet Union’s intentions, now Berlin’s own intentions are the focus of global concern. ...