what does "foreign sources" indicate?
But the apprehension of men like Bill Pozen was entirely reasonable, and they were in good company. "You'd better get the Watch Committee going," George Ball had phoned John McCone before McCone's departure for Hickory Hill, and the director had replied shortly, "I already have." The committee consisted of the sharpest eyes the CIA could focus on Moscow and Peking. Every member was a technician, expert in the intricate ways of Sino-Soviet agents, and they were to remain on the job all weekend and afterward, tapping foreign sources to determine whether or not the crime could have been the work of an outside ring.