f It is not the purpose here to consider the details of the execution of the Task Force security. However, the execution of these measures, as previously stated, was a function of all echelons of the command. Naval, Air and ground security measures were exercised by the concerned Task Groups, 7.2, 7,3 and 7.4. These actions are considered to some extent in Section 11 of this report. More detailed discussions are to be found in the individual reports of these units which are contained in Part Two of Annex One to this report. An overall consideration of security and intelligence is presented in the report of the Assistant Chief of Staff, J-2, contained in Part One of Annex One to this report. To summarize briefly the effectiveness of the security provisions devised and executed by the Task Force, the following can be stated: 1. There was no evidence of intrusions of foreign aircraft into the operational area during the course of the operation. 2. No verified reports were received at Joint Task Force Headquarters as to the presence of any foreign surface vessels within the danger area during the period of operations. 3. No evidence was developed during Operation Sandstone which indicated that any AEA Restricted Data or classified military information under Task Force control was obtained by a foreign power on unauthorized person. 4. The entire operation, from its inception to its completion, was free of any incidents of sabotage. 5. Submarine reconnaissance of the test area apparently was conducted by an unidentified foreign power. (Discussion of this effort is corItained in Section 11 of this report). It is conceivabley possible that submarine crew members or passengers may have been able to study the more prominent structures of the proving ground, such as Zero Towers, Timing Stations, and Photographic Towers. However, it is believed improbable that observations of this type were productive of any serviceable intelligence information which would be classified AEA Restricted Data. 78 —

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