| During a visit to Moscow this month, CIA Director William J. Burns stressed to the leadership of Russia's Federal Security Service and Foreign Intelligence Service that causing brain damage and other debilitating aliments among U.S. personnel and their family members would be beyond the pale for a "professional intelligence service," according to officials familiar with the exchange. The warning stopped short of assigning blame for the mysterious health incidents as U.S. investigators struggle to determine who or what is causing them. | 
