Operation Plan CTG 7.3 Ne. 1-53 be much more difficult, Uscful information by this moans could be obtained at consiccrablc distances from the Atoll. (B) To observe and chotograrh tho installations ind ¢ctonations. The linitctions of sutmarine periscope observation and photography are such that a submarinc would have to approach within three (3) miles, and prcfcrably ons (1) mile, to obtcin uscful information of shot sites. Even then, it is highly dcubtful if any dctailed information could be obtained, but only information indicating the goneral progress of work, including instrumcntation. Radar observation or radar phetogravhs could supplement the information obtained by other means, Uscful visual, radar or photographic information of the detonations could, of course, be obtained from much greater distances. Oe ReRN would rrebably result in little damoge tc installaticns or injury to personnel. On the other hand, such attacks would result in the detection and probable eventual cestruction of the submarine. While no information is available indicating that the USSR have mcdificd submarines for guidcd missile launching, there is no reasen to believe that they could not do so if they so desired, in view of the relatively simplo modifications required snd the widely publicized 0.S. accorplishments in this field. A properly directed, submarinc-leunched guided missile, fitted with an atcmic warhead, could inflict great damege to installaticns and injury to personnel and thus seriously interfcre with the Operation. USSR submarines also have the capa- bility cof attacking ships of the Joint Task Force with torpedoes. The przsence of an escort cculd indicate that the ship or ships escorted are coensiderad valuable. It is consicored that direct attack probably would preecde or accompany the opening of hostilities by the USSR, although the USSR might possibly take the risk of attempting to launch an unietected submarinc- launched guided missile in the hope that the resulting atomic -xplosion might be considered (by the U.S.) as the xccident=l or premature cxplosion of one of the test devices or a component thercof. (D) (%) Raids and Sabotage. As discussed above. Lagoon penetration could be atterpted by a submarine assigned any of the forogoing missions. However, lagoon penetraticn is not neccssary for the accomplishment of any of thom and involves definite acditicnal risks of dctection and cestruction. (2) Other YSSR Naval Gapabilitios. SSR surface ships also have enpibilitics for unauthorizzd instrunmentaticn, cbscrvation, photography, landing of raiders ond sabeteurs and dircet attack, but cxecpt as note? belcw, it is nest unlikcly their encloyment would be attomptcd, short of actual Ded