Since 1961 the United States and Russia (then the Soviet Union) have negotiated a series of nuclear weapons reduction treaties. One aspect of these treaties is the ability to verify each other’s actual holdings of nuclear weapons and “delivery systems” (silos on land and in submarines as well as bombers capable of carrying such weapons.) The United States regularly publishes data on the verified nuclear arsenals and the current count is 784 delivery systems for the United States and 528 for Russia. These systems handle 1,642 individual nuclear weapons for the U.S. and 1,643 for Russia. There are also delivery systems that still exist but are not currently used. These include 402 ICBMs (both land and sub based) for America and 458 for Russia as well as 25 launchers for the U.S. and 27 for Russia. Some of the non-deployed launchers are used for testing purposes. Each nation also has 76 unused silos on submarines. The U.S. has ten bombers that are not in service and Russia has twelve. But both nations also have nuclear warheads not covered by these treaties.
Since the end of the Cold War in 1991 both nations have dismantled over 25,000 nuclear weapons. The latest (2010) version of the START (the strategic nuclear disarmament treaty) agreement means both the U.S. and Russia will be retiring more nuclear weapons as well as delivery systems. The new treaty limits to 1,550 the number of nuclear warheads each nation can deploy.
Current plans are for the U.S. Air Force to remove nuclear weapons from 30 of 96 B-52 bombers and leave these 30 equipped only to handle smart bombs. Nuclear warheads will be removed from fifty of 450 ICBMs deployed in silos. The U.S. Navy will reduce its SSBN (nuclear ballistic missile carrying subs) force so that there are no more than 280 launch tubes holding nuclear warhead equipped missiles. Thus on each of the 14 Ohio class SSBNs four launch tubes will be modified so they cannot launch nuclear weapons. These will either be equipped with cruise missiles or satellite launchers. START also specifies the use of inspectors by Russia and the United States to ensure both sides abide by the terms of the treaty.
Meanwhile both countries are looking at the many aging delivery systems and warheads still in service. Near the end of the Cold War (1985) Russia had developed a reliable solid fuel ICBM design called Topol. This has been upgraded as their “new generation” of ICBMs in the 1990s. The United States is still using 1960s era Minuteman ICBMs. For most of the Cold War the Russian equivalent was a less efficient (and more expensive to maintain) liquid fuel design. As part of the START disarmament treaty the 1986 Minuteman replacement (Peacekeeper) was retired in 2005. A new, “START compliant” ICBM has been proposed by the U.S. Air Force, but Congress is in no mood to pay for it. Similar situation with SLBMs (Submarine Launched Ballistic Missiles) but here the American missile (Trident) is in much better shape than the Russian equivalent. The air force and navy would like a new nuclear warhead designs but Congress has not got the votes to pay for that either.
Since the 1980s, the United States has slowly reduced its once enormous nuclear weapons stockpile in Europe and in the United States. Many of these nukes are not “strategic” so are not covered by START. During the early 1970s, the United States had over 7,000 nuclear warheads stored in Europe, most of them 8 inch (204mm) and 155mm artillery shells. This was in the belief that, if the Russians, and their Warsaw Pact allies, invaded Western Europe, they would do so using these "tactical" (a yield of under 100 kilotons) nuclear weapons. Plans were drawn up to use hundreds of these warheads in battles with the invading Russians. But eventually, it was realized that such use would destroy Western Europe, and probably lead to a full scale nuclear war that would devastate the planet. So, by the end of the Cold War in 1990, there were only about 4,000 U.S. nukes left in Europe. By the end of the 1990s, there were only about 500 left. Most of these were for the use of NATO allies. During the Cold War, European nations were to be provided with American nuclear weapons, in the event of a major war. Most of these agreements are still in effect.
Russia is also believed to have disposed of most of its “non-START” nukes, many of them storied in Easter Europe, in countries that are now part of NATO. Russia withdrew all these nukes and apparently did not destroy all of them. Thus it wasn’t until 2007 that the U.S. stopped storing nuclear weapons at Ramstein airbase in Germany. These bombs were intended for the use by German aircraft, in the event of a major war with, well, there didn't seem to be any suitably scary enemies available any more. But there are still over a hundred American nuclear weapons stored in Europe, all of them believed to be 1960s era B61 nuclear weapons, configured as a half-ton bomb that can be carried by most U.S., and some European, fighter-bombers. These are not covered by START because they are used locally, not for intercontinental targets.