Question: Who deployed the ballistic missile submarines that used nuclear reactions that release nuclear energy to power them?
Context: Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range of 3,000–5,500 km (1,864–3,418 miles), between a medium-range ballistic missile (MRBM) and an intercontinental ballistic missile (ICBM).  Classifying ballistic missiles by range is done mostly for convenience; in principle there is very little difference between a low-performance ICBM and a high-performance IRBM, because decreasing payload mass can increase range over ICBM threshold.  The range definition used here is used within the U.S. Missile Defense Agency.  Some other sources include an additional category, the long-range ballistic missile (LRBM), to describe missiles with a range between IRBMs and true ICBMs.  The more modern term theater ballistic missile encompasses MRBMs and SRBMs, including any ballistic missile with a range under 3500 km . A cruise missile submarine is a submarine that launches cruise missiles (SLCMs) as its primary armament.  Cruise missile and dedicated anti-ship missiles greatly enhance a vessel's ability to attack surface combatants.  Torpedoes are a more stealthy option, but missiles give a much longer stand-off range, as well as the ability to engage multiple targets on different headings at the same time.  Many cruise missile submarines retain the capability to deploy nuclear warheads on their missiles, but they are considered distinct from ballistic missile submarines due to the substantial differences between the two weapon systems characteristics. There are three major types of submarines in the United States Navy: ballistic missile submarines, attack submarines, and cruise missile submarines. All submarines in the U.S. Navy are nuclear-powered.  Ballistic subs have a single strategic mission of carrying nuclear submarine-launched ballistic missiles. Attack submarines have several tactical missions, including sinking ships and subs, launching cruise missiles, and gathering intelligence. The "Ohio" class is a class of nuclear-powered submarines currently used by the United States Navy.  The navy has 18 "Ohio"-class submarines: 14 ballistic missile submarines (SSBN) and four that were later converted to guided missile submarines (SSGN). A ballistic missile submarine is a submarine deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads.  The United States Navy's hull classification symbols for ballistic missile submarines are SSB and SSBN – the "SS" denotes submarine (or submersible ship), the "B" denotes ballistic missile, and the "N" denotes that the submarine is nuclear powered.  These submarines became a major weapon system in the Cold War because of their nuclear deterrence capability.  They can fire missiles thousands of kilometers from their targets, and acoustic quieting makes them difficult to detect (see acoustic signature), thus making them a survivable deterrent in the event of a first strike and a key element of the mutual assured destruction policy of nuclear deterrence.  Their deployment has been dominated by the United States and the Soviet Union / Russia, with smaller numbers in service with France, the United Kingdom, China, and most recently India. USS "George Washington" (SSBN-598) was the United States's first operational ballistic missile submarine.  It was the lead ship of her class of nuclear ballistic missile submarines, was the third United States Navy ship of the name, in honor of George Washington (1732–1799), first President of the United States, and the first of that name to be purpose-built as a warship. The I-400"-class submarine (伊四百型潜水艦 , I-yon-hyaku-gata sensuikan ) Imperial Japanese Navy (IJN) submarines were the largest submarines of World War II and remained the largest ever built until the construction of nuclear ballistic missile submarines in the 1960s.  The IJN called this type of submarine Sentoku" type submarine (潜特型潜水艦 , Sen-Toku-gata sensuikan, "Submarine Special" ) .  The type name was shortened to Toku-gata Sensuikan (特型潜水艦 , Special Type Submarine ) .  They were submarine aircraft carriers able to carry three Aichi M6A "Seiran" aircraft underwater to their destinations.  They were designed to surface, launch their planes, then quickly dive again before they were discovered.  They also carried torpedoes for close-range combat.  They are considered the strategic predecessors to today’s ballistic submarines, especially to the Regulus missile program begun about a decade after World War II. 41 for Freedom refers to the US Navy Fleet Ballistic Missile (FBM) submarines from the "George Washington" , "Ethan Allen" , "Lafayette" , "James Madison" , and "Benjamin Franklin" class es.  All of these submarines were commissioned 1959-1967, as the goal was to create a credible, survivable sea-based deterrent as quickly as possible.  These submarines were nicknamed "41 for Freedom" once the goal of 41 nuclear-powered ballistic missile submarines (SSBNs) was established in the early 1960s.  The 1972 SALT I Treaty limited the number of American submarine-launched ballistic missile tubes to 656, based on the total missile tubes of the forty-one submarines, in line with the treaty's goal of limiting strategic nuclear weapons to the number already existing. The "George Washington" class was a class of nuclear-powered ballistic missile submarines deployed by the United States Navy.  The "George Washington", along with the later "Ethan Allen" , "Lafayette" , "James Madison" , and "Benjamin Franklin" classes, comprised the "41 for Freedom" group of submarines that represented the Navy's main contribution to the nuclear deterrent force through the late 1980s.
Answer: United States Navy