HEADQUARTERS, Joint Task Force SEVEN Washington 25, D.C. 10 November 1953 Annex L to CJTF SEVEN Operation Plan No, 3-53 COMMUNICATIONS 1. General Remarks a. The objectives of the basic plan are to: (1) Conduct tests, commencing in January 1954, of weapons and experimental devices in the ENIWETOK-BIKINI area to include technical and measurement programs proposed by the AEC and DOD. (2) To provide for the security of the joint task force plus ENIWETOK and BIKINI ATOLLS. b. This annex establishes the policies and general plans for the installation, maintenance and operation of communication-electronic facilities of Joint Task Force SEVEN, Further information concerning communication-electronic facilities of task groups will be found in the operation orders of the task groups. Statement of the Situation. On 21 May 1952, the JCS designated the Chief of Staff, U.S. Army as Executive Agent for an overseas atomic test operation (Operation CASTLE) and assigned the mission of the execution of CASTLE to the Commander, Joint Task Force 132. Onl February 1953, JIF 132 was administratively redesignated as Joint Task Force SEVEN (JTF SEVEN) with no change in the previously assigned mission of conducting Operation CASTLE. a. Enemy Situation. The Soviet Union has the following capabilities which may affect the accomplishment of our communication electronic mission. (1) Monitoring or Intercept. All low, medium and high frequency radio circuits are subject to constant intercept from fixed land positions or possibly from ships, aircraft or submarines. In the same manner and under favorable atmospheric conditions, VHF transmissions also are susceptible to active Soviet monitoring. (2) Jamming. Although it is not expected that the Soviets will take aggressive action to interfere with task force communicationelectronic operations, they have demonstrated their capabilities in HF jamming. There also are indications that they are prepared to jam in the VHF/UHF bands. (3) Other Interference. In addition, it is considered that interference with the commmication-electronic mission or compranise of its activities could be affected by espionage, sabotage, overt action by vessel or aircraft, raids, observations, unauthorized in- strumentation and declaration of war. b. Friendly Situation. The following activities, outside the task force, will furnish communication-electronic support as indicated. (1) National Security Agency (NSA) ~ will provide experimental APSAY 80], (x) ciphony equipment for the USS ESTES firing party circuit. Le1