HEADQUARTERS, Joint Task Force SEVEN Washington 25, D. C. 20 June 1953, 2600 R Annex C to CJTF SEVEN Operation Order No. 1~53 INTELLIGENCE, SECURITY AND PUBLIC INFORMATION intelligence = General a. No interference is expected from an overt enemy during Operation CASTLE since the use of force or direct open observation from a point well within the ENIWETOK-BIKINI danger area would involve consequences out of proportion to the value of the results to be obtained from such action, b. The country having the greatest capability of compromising the security of Operation CASTLE is the Soviet Union. c. In the event of an outbreak of war the entire concept of the opera- tion would be changed materially. Summary of Enemy Capabilities a. It is considered that interference with the mission or compromise of its activities could be effected by espionage, sabotage, overt action by vessel or aircraft, raids, observation, unauthorized instru- mentation and declaration of war. Naval Capabilities. c. Air Capabilities The USSR has 19 ocean patrol and 37 medium Tay b. range type submarines in the Pacific area. It is estimated that at least 4 to 6 ocean patrol submarines could be maintained in the ENIWETOK-BIKINI operational area indefinitely and for short periods this number could be increased. Unobserved submarine approach within one mile of important islands of these atolls is possible. (1) Aerial photo and radiological reconnaissance of the ENIWETOKBIKINI area from Far East bases (SAKHALIN or the KURILES) are within Soviet capabilities. With prior access to CASTLE plans, reconnaissance flights could be properly timed to permit aircraft to remain in the target area for a brief period. The TU-4, modified for long range reconnaissance, could accomplish this without refueling. Assuming that the Soviets have developed refueling techniques equal to those of the U.S., one outbound refueling would extend the time over target to over 4 hours. There is no evidence, however, that the Soviets have developed refueling capabilities. The Third Long Range Air Army, stationed in the Far East, is presently estimated to have a TO/E strength of approximately 220 TU-4s. No aircraft of this type (2) The only Soviet aircraft known to have greater range potentiality than the TU-4 is the Type 31 prototype heavy bomber which was observed in flight for the first time in the July 1951 Aviation Day air show in Moscow, This aircraft, if equipped with the JU-022 turboprop engine, would have a combat radius of about 3500 nautical miles and considerably in excess of this if the combat load were replaced with fuel. A few aircraft are probably available having range C-1 Rev. 7-25-53 Ch. Le is known to be modified for long range reconnaissance.