Targeting 'Eagle Base'

The conversation was in code, but to trained ears it was easily understood. Picked up by American listening devices on Oct. 16 in Sarajevo, it ranged from the U.S. bombing in Afghanistan to "what the response should be here," a senior Bosnian official told TIME.

U.S. and British targets in Bosnia were mentioned. But it was the resolute sign-off that got listeners attention: "Tomorrow, we will start."

Both countries shut down their embassies and branch offices overnight. Using mobile phone card registration numbers, Bosnian police tracked down and arrested both callers — Algerian...