In response to your letter of 21 October 1974, a copy of the minutes of the 4 December 1952 meeting of the Intelligence Advisory Committee relating to the discussion of "Unidentified Flying Objects" is enclosed. Following this meeting selected scientists reviewed and appraised the available evidence on the subject. A copy of the report of this review, titled "Report on Unidentified Flying Objects", dated 17 January 1953 is enclosed. In view of the conclusion of the Panel that the evidence presented on unidentified flying objects showed no indication that these phenomena constitute a direct physical threat to national security, no National Security Council Intelligence Directive (NSCID) was drafted.