The end of the Cold War removed the Soviet fleet, the only major force confronting the U.S. Navy. Oh there were still a few Russian boomers putting to sea from time to time, and even fewer (and easier to track) Chinese boomers. Russia had been trying for decades to catch up with the United States in nuclear submarine design, but the collapse of the Soviet Union put an end to that effort. Oh, the effort was still going on, and the Russians had some very capable SSNs, but the money just wasn't there any more. In effect, the end of the Cold War left the U.S. SSN fleet with no one to play with.
But like any service, the navy had it's "unions" for each major branch. The surface warship, amphibious, sea transportation, mine warfare and carrier unions still had work to do after the Cold War ended. But the bubbleheads (as the submariners are known) were in much less demand. But these unions exist to lobby for their interests, and the bubbleheads began making a lot of noise about how harmful cutbacks would be to their essential missions. The problem was that most of their missions had either disappeared or could be carried out more cheaply with surface ships. In the early 1990s, the navy planned to cut the SSN fleet to 50 subs (plus 18, or fewer, boomers, which are covered arms control agreements). The bubblehead union fought back, and, despite having no meaningful arguments, are winning. Although the current SSN fleet is 55 subs, work is proceeding on building 30 new Virginia class SSNs and not retiring older boats as they come due for refueling their nuclear reactors (a very expensive process.) The Cold War era Seawolf SSN program was cancelled in the early 1990s, after only two were built, because of the cost ($3 billion each.) The new Virginias will cost about 20 percent less than that. But to justify the Virginia, the current Los Angeles class boats will have to be retired 10-20 years before their planned 30 year service life is up. And the Los Angeles class could have their lives extended 10 or more years beyond their 30 year service life. Naturally, the bubbleheads would prefer to keep a lot of the older SSNs, and just add the new Virginias. But first they have to convince Congress to provide hundreds of billions of dollars to make this happen.
So while the navy pleads poverty when it is asked why there are not more high speed transports, mine warfare ships improvements for existing ships (more automation to reduce crew size and better guns for supporting ground forces operating on the coast), it is spending billions of dollars a year on subs it doesn't need. The bubbleheads convinced congress that SSNs were excellent for launching cruise missiles (something surface ships do more cheaply), chasing drug smugglers and defending American ships against hostile submarines that exist only in the imagination of fear mongering bubbleheads. These "forecasts" stipulate a need for 68 SSNs by 2015 and 76 by 2025. These numbers are arrived at by taking useless missions carried out in the 1990s and assuming there will be a greater need for pointless cruises in the future. Many in the navy are beginning to ask questions about how relevant the decades old policy of "forward deployment" (having ships spend a substantial amount of time at sea) is. For one thing, it's becoming more and more difficult to recruit people willing to put up with those long peacetime cruises. Crew shortages have been getting worse through the 1990s, and recruiting qualified people to operate SSNs is one of the more difficult tasks. And you can't argue with the bubblehead union. They are on a mission of undisputable value (at least to a bubblehead, your mileage may vary.)
Despite decades of diligent and skillful service during the Cold War, only one SSN has ever fired a shot in anger. In 1982, a British SSN sank a World War II era cruiser with a World War II era torpedo. But SSNs are likely to set records for peacetime spending, and not much else.
Little noticed since the end of the Cold War is the curious position of the nuclear submarine. It's now basically an expensive weapons system without any real purpose. Developed in the late 1950s, these vessels were hailed as the perfect submarines. The "nukes" (or SSN, as nuclear attack subs came to be known) could stay underwater for months at a time, slowly, and silently, patrolling. Larger nukes, carrying ballistic missiles, became crucial strategic weapons, as each of these "boomers" (also known as SSBN) could kill millions of people. A principal function of the SSN was to hunt enemy boomers, or protect your own. Unlike in the two World Wars, submarines, at least the nuclear ones, were no longer intended mainly for attacking enemy shipping. Submarines were originally designed for going after warships. But these vessels were faster than subs, more heavily armed and soon equipped with equipment (sonar) that could detect submerged submarines. So the subs went after cargo ships, which were equally, if not more, important to the enemy war effort. But the nukes changed all that. Nuclear subs were a lot more expensive, so you had a lot fewer of them. And the nuclear subs didn't carry many more torpedoes than the older diesel-electric submarine designs. In fact, the main threat to the Western Worlds merchant fleet would have been several hundred Soviet diesel-electric subs. The nukes were considered "capital ships," not minor players, or "boats" as the non-nuclear subs had been.