Operation Ivy Bells was a joint United States Navy, Central Intelligence Agency (CIA), and National Security Agency (NSA) mission whose objective was to place wire taps on Soviet underwater communication lines during the Cold War. Background During the Cold War, the United States wanted to learn more about Soviet submarine and missile technology, specifically ICBM test and nuclear first strike capability. In the early 1970s the U.S. government learned of the existence of an undersea communications cable in the Sea of Okhotsk, which connected the major Soviet Pacific Fleet naval base at Petropavlovsk on the Kamchatka Peninsula to the Soviet Pacific Fleet's mainland headquarters at Vladivostok. At the time, the Sea of Okhotsk was claimed by the Soviet Union as territorial waters, and was strictly off limits to foreign vessels, and the Soviet Navy had installed a network of sound detection devices along the seabed to detect intruders. The area also saw numerous surface and subsurface naval exercises. Installation Despite these obstacles, the potential for an intelligence coup was considered too great to ignore, and in October 1971, the United States sent the purpose-modified submarine deep into the Sea of Okhotsk. Funds for the project were diverted secretly from the deep-submergence rescue vehicle (DSRV) program, and the modified submarines were shown with fake DSRV simulators attached to them. These were early diver lockouts. US Navy Divers working from Halibut found the cable in of water and installed a long device, which wrapped around the cable without piercing its casing and recorded all communications made over it. The large recording device was designed to detach if the cable was raised for repair. The tapping of the Soviet naval cable was so secret that most sailors involved did not have the security clearance needed to know about it. A cover story was thus created to disguise the actual mission: it was claimed that the spy submarines were sent to the Soviet naval range in the Sea of Okhotsk to recover the Soviet supersonic anti-ship missile (AShM) debris so that countermeasures could be developed. Although created as a cover story, this mission was actually carried out with great success: U.S. Navy divers recovered all of the SS-N-12 debris, with the largest debris no larger than , and a total of more than two million pieces. The debris was taken to the U.S. and reconstructed at the U.S. Naval Research Laboratory. Based on these