War of Secrets; Not Much Has Changed in a System That Failed
Special section, Unseen: War of Secrets; US intelligence agencies, harshly criticized after Sept 11 terrorist attacks, have had surprisingly little restructuring in months since; broad debate has begun on reorganizing domestic and foreign intelligence in face of supple, unfamiliar and suicidal new form of threat; CIA and FBI prove resilient in defending turf, although some legal restrictions on information sharing have been lifted and senior officials can now work more closely together; other proposals working way through bureaucracy are certain to be altered or quashed by interagency battles; one that would give defense secretary more authority over major military intelligence agencies might diminish CIA director's role; CIA Dir George Tenet's close ties with Pres Bush clearly helps him withstand crisis and FBI Dir Robert Mueller has become strong advocate of keeping FBI intact; Congress looks to incremental changes because committee structures mirror turf of executive branch agencies (M)