The U.S. Navy currently deploys almost one-half of all U.S. nuclear weapons. The total number of U.S. "nukes" is declining, while the percentage of U.S. weapons on board ship—specifically, in 18 Trident missile submarines—is increasing.
Today, the United States has almost 7,500 nuclear warheads, down from about 20,000 when the Cold War ended in 1991. They are carried by land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), manned strategic bombers, and manned tactical bombers in Western Europe. Table 1 shows an estimate of current U.S. nuclear weapons assigned to operational forces.
Long gone are the approximately 500 shipboard nuclear weapons that populated U.S. warships in the final days of the Cold War—some 400 B57 and B61 strike bombs and depth bombs in aircraft carriers, and 100 Tomahawk land-attack missiles (TLAMs) in cruisers, destroyers, and attack submarines. Similarly discarded are the B57 nuclear depth bombs assigned to P-3 Orion maritime patrol aircraft.
According to Navy sources, a residual capability remains in surface warships and attack submarines for Tomahawks fitted with the W80 warhead, a 5- to 150-kiloton weapon. But the missiles were beached several years ago, and crews have received minimal training and have had few exercises in handling and launching nuclear Tomahawks. This capability must be considered essentially negligible.
SLBMs. The U.S. Navy's only realistic nuclear capability is found in the 18 Trident missile submarines of the Ohio (SSBN-726) class. These boats, completed from 1974 to 1991, each carry 24 missiles. The first eight have the Trident CX missile with eight W76 100-kiloton warheads; the ten later Ohios have either eight W76s or eight W88 50kiloton warheads. Together, the SSBNs provide almost 50% of the U.S. strategic warheads and some 27% of the U.S. strategic megatonnage.
Under the signed but not ratified START II agreement between the United States and Russia, the total number of U.S. strategic nuclear warheads is to be reduced, with no more than 1,750 deployed on strategic missile submarines (see Table 2). The current U.S. strategic force of 18 submarines with 432 SLBMs would be reduced to 14 submarines loaded with 336 D-5 missiles, i.e., four submarines would be discarded and four would be upgraded from the C-4 to the more accurate D-5. But the U.S. Congress has not approved START II, and the Russian parliament (Duma) is considered highly unlikely to do so in the foreseeable future.
Still, the U.S. defense budget probably will not continue to support 18 SSBNs. The force can be expected to be reduced to 14 submarines, if not fewer, within the next few years, whether or not START II is ratified. In addition, the emphasis on conventional forces could lead to a further reduction; some Air Force documents have addressed a strategic force including only 10 Trident submarines with 240 missiles.
If START II is approved, the number of warheads per missile will be reduced from the nominal eight to five-plus to meet treaty requirements (i.e., 14 submarines x 24 missiles x 5.2 warheads = 1,747).
At present, there are no SSBN or SLBM development programs. D-5 missiles still are being produced at a slow rate to arm the Ohio-class submarines, as well as the four British Trident-armed submarines of the Vanguard class.
ICBMs. The U.S. land-based strategic missile force has been reduced from more than 1,000 ICBMs in the late 1980s to the current force of 550. All are multiple-warhead missiles. The Minuteman III missiles are being consolidated in hardened silos at three sites in North Dakota, Montana, and Wyoming; the MX missiles are in silos in Wyoming.
The Minuteman missiles each carry three warheads; 200 carry the 170-kiloton W62, and 300 have the W78, with a yield estimated at 335 kilotons. The MX missiles each carry ten warheads, the 300 kiloton W87. Thus, SLBMs carry significantly more warheads, but ICBMs carry more megatonnage.
If START II is ratified, the 50 MX missiles (which became operational in 1986-1988) would be discarded. In addition, the 500 surviving Minuteman IIIs would be rearmed with single warheads; most of these would be W87 warheads taken from the MX missiles.
No new ICBM is under development and, of course, none is being produced at this time.
Heavy Bombers. This is the strategic arms limitation term for long-range strategic bombers. Three types are now in service:
- There are 94 B-52H Stratofortress six-jet bombers, the last of which was completed in 1962. Each can carry up to 20 nuclear cruise missiles or conventional bombs. (B-52s were used in the Vietnam and Gulf wars carrying conventional bombs.) Only some 44 B-52s are fully operational, the others being used for research or training, or are in overhaul.
These aging giants will be flown well into the 21st century.
- The other nuclear-capable heavy bomber is the B-2 Spirit, the stealth aircraft with a flying-wing configuration. Only 21 of these aircraft are being produced. At this time, about 10 are fully operational. Each can carry up to 16 B61 or B83 nuclear bombs, or conventional weapons.
- A third heavy bomber, the B-1 Lancer, is in service. However, the 94 aircraft—of which some 48 are fully operational—are configured only for conventional weapons.
Heavy bombers provide a large number of warheads, as well as a major part of the U.S. megatonnage. Under START II, the number of nuclear-capable heavy bombers would be fixed at 92, the 71 B-52Hs and the 21 B-2s. Although no future heavy bomber procurement is envisioned, considerable funds are being spent on updating all three aircraft. Against sophisticated defenses these aircraft require the support of stand-off jamming planes, a role assigned to Navy-Air Force EA-6B Prowlers. In addition, long-range strikes would require refueling support from KC-10 Extender and KC-135 Stratotanker aircraft.
Fighter Aircraft. The only other U.S. nuclear-capable forces are F-15E Eagle and F-16C/D Fighting Falcon "fighters" based in Europe. About 150 B61 bombs, with a variable yield from 100 to 500 kilotons, are at bases in seven countries—Belgium, Britain, Germany, Greece, Italy, the Netherlands, and Turkey. These are the only nuclear weapons maintained by any country at bases outside of its national borders. In addition to the U.S. planes, strike aircraft of Belgium, Holland, Greece, Germany, Italy, and Turkey could carry the B61s.
These nuclear weapons are not addressed in the START agreements.
There are many arguments for retaining a U.S. nuclear capability. Beyond Russia and China, which are not military antagonists to the United States, several other nations possess nuclear weapons. These are considered to be friendly toward the United States (Britain, France, Israel) or neutral (India, Pakistan), but other countries in a third category are seeking nuclear weapons. These last include Iraq and North Korea, and possibly Iran. And there is the potential threat from transnational terrorist organizations that would purchase or steal rather than develop nuclear weapons.
U.S. nuclear weapons could be considered a viable deterrent to the use of nuclear weapons against the United States and certain allies. Also, nuclear weapons are considered as a deterrent (or retaliatory weapon) against other weapons of mass destruction, i.e., chemical and biological devices. Israel, for example, certainly considered the use of nuclear weapons as a counterstrike had Iraq employed such warheads in the modified Scud missiles it fired at Israel during the Gulf War. Even the U.S. government did not rule out the use of nuclear weapons against Iraq if chemical or biological weapons were employed against U.S. forces.
Although the likelihood of START II being ratified in the near future is slim, the United States undoubtedly will move toward the START II level of nuclear forces. There are insufficient funds available to maintain even the planned conventional U.S. forces. Over the past three years Congress has added $21 billion above the president's defense spending requests. Still, in late September the U.S. service chiefs told Congress of "planes that cannot fly, units that are ill trained, and too many good people who have had enough [and] are calling it quits." The Joint Chiefs of Staff recently told Congress that another $20 billion is required for readiness, pay, and retirement.
Defense spending is now 2.9% of the gross domestic product—the lowest level since before the Japanese attack on Pearl Harbor in 1941. Having achieved a budget surplus in fiscal year 1998, the White House is unlikely to approve a major increase in defense spending, nor will a Republican Congress whose motto is "reduce taxes."
There will be more defense cuts, to develop a still smaller but more efficient and better trained military force. And nuclear weapons, which are relatively expensive to maintain, will be a prime target for those seeking additional funds for conventional forces.