2h; SECURITY Operation GREENHOUSE began during a period of growing international tension. The USSR was given the capabilities of interference with or the compromise of the mission of JTF-3 by cspionage, sabotage, overt action, observation or unauthorized The foundation of JIF-3's security policy and the primary safeguard instrumentation. against penctration of JTF-3 by foreign espionage was the "Q" clearance of all per— In February 1951, cortein sonnel] who were to have any access to RESTRICTED DATA. changes were made in the Department of Defense's policy on access to RESTRICTED DATA by military personnel. RO" clearances. However, JTV-3 held consistently to its policy of straight In addition to these clearances, National Agency Cheeks and other types of investigation were applicd to the remainder of JTF-3 personnel who were not to have access to RESTRICTED DATA, The island gcography of the atoll lent itself well to tho establishment and control of #ACLUSTON and RESTRICTED «reas, all of which were guarded by military police. By a system of security control badges and access lists the traffic of personnel was Limited to the necessities of their jobs. One security measure did cause individual delays at HONOLULU and KWAJALEIN end it involved a greater volume of communication traffic than should have been necessary. (JTF-3 agreed to comply with CINCPAC Serial 0116 which required a prior dispatch on all persons entering the ENIWETOK Danger Arca). To counter possible hostile mili- tary actions or reconnaissance threats, air and sea reconnaissance of the Danger Area and ground and air reconnaissance of the atoll was conducted. The forces avail— able in the event of emergency included two destroyers, a squadron of P2Vs, a flight of six F-S0C intereceptors snd 227 military police, reenforeud by a limited number of Army personnel. for whom arms and ammunition were stocked. During the actual test period there was only one known violation of the Danger Area; a Japanese fishing vessel, Out of all the reconnaissance sightings 2nd reports there emerged only one identified "possible submarine" and this was about 130 miles outside the Danger Area, There is no reason to believe foreign powers penetrated the Danger Area by sea or air, 23. LOGISTICS a, CONSTRUCTION The construction program on ENIWETOK ATOLL was initieted in October of 1947 by the AEG through the firm of Holmes and Narver, LOS ANGELES, CALIFORNIA. Task Group 3.2 augmented the contractor force. The construction effort consist— ed of both rehabilitating World War II structures and in constructing new faci- 15 b Eee ~~ Mie doee het a bP re aca fon DerikhoES ?