C.I.A. Is Reviewing Its Security Policy for Recruitment
CIA is reviewing stringent security rules that turn away large numbers of badly-needed Arabic speakers and other potential recruits with skills sought since 2001 terrorist attacks; many are first-generation Americans who have linguistic facility and cultural knowledge agency needs to gather intelligence and penetrate terrorist groups; many also have relatives abroad, posing problem for background checks and potential blackmail; CIA has strictest guidelines in government, recruiting only US citizens with top-secret clearance and only those under age 35 for clandestine work; officials caution that in some cases security concerns have been well-founded; spokeswoman Jennifer Millerwise explains recruiting; House intelligence committee urges director John D Negroponte to use skills of unconventional hires (M)