Apr. 15, 1962 - Another indication of deepening U.S. involvement in South Vietnam’s campaign against the Communist guerrillas called the Viet Cong was the arrival in Saigon today of a Pentagon study group that included Allen W. Dulles (pictured), former chief of the C.I.A. The group will try to determine whether the 6,000 U.S. military personnel assigned to the South Vietnamese forces as advisors, trainers, and transport assistants really know why they are in Vietnam and what they are doing. The group will also study morale and indoctrination. Last week it visited the Philippines, where it investigated the nature of the briefings on Southeast Asia given to U.S. troops in transit for South Vietnam.