MANPOWER SLASH IN MARINES, NAVY BACKED WITH 'IFS'; MANPOWER CUTS BACKED WITH 'IF'
Sec Thomas, Carney and Gen Shepherd back USN and USMC cuts, subcom; Shepherd admits he did not suggest cuts, says they will sacrifice staying power, but holds readiness of Corps' basic striking force will not be impaired; Carney urges US maintain naval superiority; warns of USSR gains; Ridgway to testify