IT is a half century since the foreign intelligence system of the United States was established by the National Security Act of 1947. It is 80 years since the Espionage Act of 1917 established the present legal regime dealing with subversive activities within the United States itself. This has been a time of war and rumors of war without cease, global ideological conflict, and, with the onset of the atomic age, the possibility, at times even the prospect, that the human race might destroy itself in one climactic armageddonic convulsion.