FOREIGN RELATIONS: Troubleshooter

Currently the hottest spot in U.S.diplomacy is a stone-faced building in the heart of busy Belgrade, capital of Tito’s Yugoslavia. From its shadowed rooms, lanky, sharp-featured Cavendish Cannon, 54, had done one of the cold war’s outstanding jobs. He sniffed trouble in the air before the Tito Cominform split burst into the open, then begged his superiors to give Tito’s government the encouragement and limited support it needed to keep the rebellion thriving, without buying Tito’s own party line. But Cannon had worked himself into a state of exhaustion and a case of stomach ulcers. Last week he packed his bags and headed homeward for a rest and a new assignment.

To replace him, the State Department picked another career diplomat: George V. Allen, 45, onetime chief of the department’s Middle Eastern Affairs division. As U.S. ambassador to Persia from 1946 to 1948, George Allen had served in another trouble spot during a troubled time, with conspicuous success. Recalled to Washington in 1948, he was appointed Assistant Secretary of State for Public Affairs (i.e., propaganda chief) and took over the job of giving vigor and consistency to the quavering Voice of America. The U.S.S.R. gave him the firmest recognition of his work; it put more than 200 stations to the job of jamming the Voice, has not yet succeeded in fully muffling its programs.