Strategic deterrence at sea became an indispensable part of the US Navy’s wartime missions it has to perform in the 1970s and 1980s. The goal was to dissuade the Soviet Union from launching a nuclear attack. Submarine-launched ballistic missiles (SLBMs) were playing a key role in the strategic deterrence mission by providing the United States with a second-strike capability. In 1980-1981, the Soviet Union was constantly improving its own SLBM submarine force in capability and capacity. At the same time, the US Navy’s SLBM submarine force has further declined in absolute numbers vis-a-vis the Soviet fleet. The Soviet Union, which test-fired their first SLBM as early as September 1955, deployed the R-29D/SS-N-8 (‘Sawfly’) intercontinental ballistic missile (ICBM) aboard Delta class ballistic missile submarines from 1973 that could remain in protected waters and with the 4,200-nautical mile missile target all major cities on US mainland. Naval journalist, analyst and writer Norman Polmar, in a five-page assessment about sea-based strategic weapons noted that Soviet SLBMs were in reality “mobile ICBMs” as much as sea-based strategic weapons, offering most of the advantages of both types of strategic weapons. By late 1981, the Soviet Union had at least 62 SLBM submarines armed with over 950 nuclear missiles, compared to only 31 ballistic missile submarines with 496 missiles in the US Navy. The so-called “Sea Plan 2000” prepared by the Director of Strategic Research under the auspices of the Naval War College expected that the total operating submarines with SLBM capability would further decline to 25 boats until at least the late 1980s or early 1990s. Therefore, the Navy’s SLBM submarine force was in strong demand of modernisation that resulted in the withdrawal of the first of the oldest “41 for Freedom” nuclear-powered ballistic missile submarines (SSBNs). From 1960-1969, each boat carried 16 Polaris nuclear missiles. In 1969, they were converted to carry the more accurate Poseidon missiles, which would change again in 1979 when the 4,000-nautical mile, multiple-warhead Trident I (or Trident C-4) missiles were created. At the end, 18 Ohio class SSBNs, commissioned between 1981 and 1997, replaced the “boomers”. Four of them became guided missile submarines (SSGNs) after the 1994 Nuclear Posture Review recommended the US only needed 14 SSBNs to meet strategic deterrence needs.
