For an update please notice the May 2001 BITS press release
"Larger Nuclear Weapons Storage Facilities in Europe"

BASIC-BITS-Research Note 97.1
February 1997

U.S. Nuclear NATO Arsenals 1996-97

Otfried Nassauer, Oliver Meier
Nicola Butler, Stephen Young

Fewer U.S. Nuclear Weapons, More Flexible Warfighting

The United States in all probability deploys many fewer nuclear warheads in Europe than previously assumed. Information received from the U.S. Department of Defense by the Berlin Information-center for Transatlantic Security (BITS) and the British American Security Information Council (BASIC) strongly indicates that currently there are about 200 U.S. nuclear bombs deployed on European sites. 700 nuclear bombs were said to be deployed according to the latest official figures published by NATO some years ago. 480 nuclear bombs were said to be deployed on European soil during recent years. NATO sources, on the condition of unanimity, mentioned a figure around 200. They confirmed that besides the 1991-1993 reduction program resulting from the Taormina meeting of the Nuclear Planning Group, another reduction process scheduled to be completed by 1998 is currently underway.

However, NATO clings to its nuclear warfighting capability. NATO's new military strategy, MC 400/1, approved at the North Atlantic Council meeting on June 3rd, 1996 commits the alliance to maintain a reduced, but more flexible nuclear posture for the foreseeable future. It does not revoke NATO's long-standing policy of keeping the option of a "first use" open. It does not commit NATO to use nuclear weapons only as a last resort. While the main purpose of nuclear weapons is said to be political, nuclear weapons are described as playing an essential stabilizing role in Europe, guarding against uncertainties (such as risks resulting from proliferation of weapons of mass destruction) and as serving as a hedge, in case a substantial military threat to NATO re-emerges.

NATO will no longer maintain detailed nuclear war plans for the use of sub-strategic and/or strategic nuclear weapons in specific scenarios. Instead it will develop an "adaptive targeting capability" allowing Major NATO Commanders to develop target- and nuclear weapons employment plans on short notice during contingency or crisis from pre-developed databases about possible targets. NATO will reduce the number of dual capable aircraft units fully trained and ready to conduct nuclear missions in peacetime. Instead, the capability to redeploy such aircraft from one NATO region to another will be increased. In peacetime each NATO country operating dual capable aircraft in future will be required to maintain only one unit fully trained and ready for nuclear missions.

NATO's nuclear warfighting capability is strongly supported by a parallel modernization program for nuclear weapons storage sites on NATO airbases. In 1987, the U.S. and - following suit - NATO decided to install "Weapons Storage and Security Systems (WS3)" on all major European airbases. These storage systems allow for nuclear weapons to be deployed underneath the aircraft within vaults constructed into the floor of the hardened aircraft shelters. The system is said to protect the weapons against physical intrusion for a minimum of 30 minutes and to allow for remote-control of the safety status of weapons by built-in sensors.

The current construction program for these new weapon storage systems totals 208 vaults on 13 airbases. (For locations see map in Annex A). Since each vault probably holds one weapon (see photograph in Annex B), the new storage capacity once completed can host 208 weapons. The actual number of weapons deployed may be less (e.g. NATO currently does not store weapons in 22 vaults built at Memmingen and Noervenich airbases in Germany). When developed and contracted in 1987 and 1988, the requirement for the new storage system was to build 437 vaults at 26 locations. However, during a lengthy post-Cold War review process, NATO's Senior Level Weapons Protection Group, the so called SLOWPIG working group, decided to cut the program by more than 50 percent.

Since 1990, vault systems have become operational on eight bases in five European countries: Germany, the United Kingdom, Italy, Belgium and the Netherlands. Five additional bases in Italy (1), Greece (1) and Turkey (3) are still to be modernized. The United Kingdom, in its own modernization program, installed vaults at one airbase in the United Kingdom and one in Germany. With the new storage system in place, special ammunition storage igloos which held nuclear warheads throughout the Cold War have been shut down.

While in public it has been widely debated whether NATO might deploy nuclear weapons in its future new member states, currently no indications exist, that NATO plans to act contrary to its December 10, 1996 statement saying that the Alliance does not intend to do so. However NATO resists any binding commitment and thus retains the right to deploy nuclear weapons on new members' territory during crisis or war. Furthermore NATO has not officially foreclosed a future decision to construct nuclear weapons storage infrastructure in these countries.

Germany Still Hosts Largest Storage Capacity

Germany still has the largest capacity to host foreign nuclear weapons. Fifty-eight vaults, the highest number installed on a single base, have been built at Ramstein Airbase, which also hosts the US Air Force Europe Headquarters. Eleven vaults each have been constructed in addition at three German Air Force (GAF) main operation bases, Memmingen Airbase, Noervenich Airbase, and Buechel Airbase. The GAF operates one wing of dual-capable Tornado aircrafts at each of the three airbases. Since the construction programs at all bases in Germany were finished before they could be affected by the SLOWPIG review process, it is assumed here that the original number of vaults planned and financed for these bases has been built. Probably a total of up to 91 U.S. nuclear weapons can be stored in these more modern and safer storage bunkers. Since Britain bought and installed a 10 vault system for its Royal Air Force Base in Brueggen, the total nuclear weapons storage capacity for Germany is 101 vaults.

Under a new NATO’s policy, two of the GAF airbases do not host nuclear weapons during peacetime. They were removed from Memmingen and Noervenich airbases by the second half of 1995. GAF special guard units were also dissolved. Germany is required to maintain only one unit of dual-capable aircraft fully trained and ready for nuclear missions. This unit is the 33rd Fighter Bomber Wing at Buechel Airbase, nominally equipped with 36 Tornado IDS aircraft. The maximum number of U.S. nuclear weapons to be stored in vaults during peacetime on German soil thus should not exceed 80.

Holland and Belgium Retain Nuclear Weapon Storage Capacity

Both Belgium and the Netherlands retain the capability to store nuclear weapons on their soil and to participate in NATO nuclear operations. Each country has one main airbase for storing nuclear weapons to be used with F-16 dual-capable fighter-bomber aircraft: Volkel airbase in Holland and Kleine Brogel airbase in Belgium. At Volkel, 11 vaults reached initial operational capability on September 13, 1991; at Kleine Brogel the same change took effect on April 3, 1992. Both countries thus fulfill NATO's new requirement, that all countries participating in Programs of Cooperation should maintain one nuclear capable unit fully operational.

U.S. Department of Defense Reveals British Airbases to Have Nuclear Weapons Storage Capacity

The U.S. Air Force's Electronic Systems Center accidentally revealed a British national secret. Marham Air Base in Britain and Brueggen Air Base in Germany are two Royal Air Force airbases having the capability to store nuclear weapons. The On July 18, 1995 the Hanscom Air Force Base Electronics Systems Center issued a little-noticed press release announcing the $ 24 million sale of 34 "Weapon Storage and Security Systems" (WS3), providing "storage of tactical nuclear weapons within the floors of hardened aircraft shelters" to Britain. The release stated 24 vaults were installed at Marham Air Base in Britain by May 1995, and ten more at Brueggen Air Base in Germany by June 1995. These vaults became available because the SLOWPIG decision to reduce the number of vaults occurred only after 257 vaults were built, leaving an excess of 49.

The only U.S. airbase in Britain to host nuclear weapons storage vaults is RAF Lakenheath. It is likely that 30 vaults have been installed and reached initial operational capability on November 18, 1994. While originally 48 vaults had been planned for this Airbase, Lakenheath is the only airbase for which the concrete change to the WS3-program resulting from the SLOWPIG review process is known. This clarifies reports in the British press that the nuclear weapons at Lakenheath might have quietly been withdrawn. They have been relocated to vaults, a much less visible storage method.

The British investment in a safer nuclear weapons storage system for its WE 177 free fall bombs came late and proved to be an unnecessary expense. While the Foreign Military sales contract with the United States was signed in late 1993, construction began in late 1994. Construction was completed in June 1995, only two months after the British government had decided to retire all WE 177s by 1998. It will give up Brueggen Airbase by 2002.

Emphasis now on NATO's Southern Flank

Current construction activities concentrate on NATO's southern flank. All AFSOUTH air bases planned to host U.S. nuclear weapons in the late 1980s were reviewed by NATO's SLOWPIG group. The number of bases and vaults planned for AFSOUTH decreased. The same is true for AFCENT and especially the United Kingdom. However, the decrease is smaller for the latter and this reflects the increased emphasis NATO is giving to its southern flank. Construction work at the airbases of AFSOUTH is incomplete at all but one base.

By January 1996, Aviano airbase in Italy had become the first AFSOUTH base to receive the new storage system. In 1987, it had been planned that Aviano should host 18 vaults. Ghedi Torre, an Italian Air Force base, has been chosen to host the nuclear weapons storage vaults for Italian dual-capable aircraft. Initial operational capability had not yet been reached by late 1996.

Greece's participation in NATO nuclear operations will be maintained by the country hosting nuclear weapons at Araxos airbase. 11 vaults were preplanned for Araxos in 1987. It is not known whether the number has been reduced in the SLOWPIG review process.

Turkey will receive nuclear weapons storage vaults at three airbases. None of these construction projects had been completed by late 1996. Incirlik airbase, which is used by the USAF on a regular basis, has probably been selected to have the largest storage capacity in Turkey. Nevertheless, the number of vaults that will be built is likely to be smaller than 30 planned in 1987. Two other airbases, Murted and Balikesir, which are both operated by the Turkish AirForce, will host smaller quantities of vaults. In 1987, it had been planned, that six vaults each should be constructed. As with Germany, under the new NATO policy of keeping only one unit in each country operating nuclear capable aircraft intended for the use with U.S. nuclear weapons under a Program of Cooperation, it is highly likely that only one base in Turkey, presumably Incirlik, will actually host nuclear weapons during peacetime.

NATO wants to complete the whole construction program by 1998.

NATO Enlargement and Nuclear Weapons Deployment

NATO nuclear weapons have become a disputed subject in the context of NATO-enlargement. Facing strong Russian opposition to NATO-enlargement and especially the possibility that nuclear weapons might be deployed nearer to Russia's borders, the North Atlantic Council announced on December 10, 1996 that „enlarging the Alliance will not require a change in NATO’s current nuclear posture, and therefore, NATO countries have no intention, no plan, and no reason to deploy nuclear weapons on the territory of new members nor any need to change any aspect of NATO’s nuclear posture or nuclear policy - and we do not foresee any future need to do so." Then U.S. Secretary of State, Warren Cristopher, added that "no NATO nuclear weapons are presently on alert".

However the decisive question, whether infrastructure for nuclear weapons deployment will be built in the new member states has been avoided in the statement. Current plans for constructing nuclear weapons storage vaults do not indicate any concrete plans to deploy such weapons in any of the new member states. Nevertheless these plans were finalized prior to NATO's decision to take up new members. Furthermore, NATO strictly refuses to make this political statement a legally binding one, as NATO Secretary Solana emphasized recently. At the same time, new members are supposed to play a role in NATO nuclear policy. They are eligible „to join the Nuclear Planning Group and its subordinate bodies and to participate in nuclear consultation during exercises and crisis." Thus it remains an open question whether NATO would stick to its commitment not to deploys nuclear weapons in new member states during crisis or war or even should the international situation change. The decision whether to build nuclear weapons infrastructure in new member countries is likely to be made when these countries are members. Furthermore it remains open how NATO would answer a request by one or several new members for participation in nuclear sharing arrangements to include deployment on their soil. None of the possible members yet has made a decision to buy Western nuclear certified aircraft.

The Weapons Storage and Security System

process of modernizing NATO's nuclear weapons storage system began in 1988. For most of the Cold War, NATO main operation bases participating in NATO's Quick Reaction Alert task held small numbers of nuclear bombs ready at hand and in on-base nuclear weapons bunkers. Most nuclear warheads for use with these airbases were stored in separate nuclear weapons storage sites. In some cases, these sites were part of the airbase, but in others the igloos were often located several miles from the aircraft shelters. Transporting the munitions "requires convoys with large security forces traveling through unrestricted areas. The very presence of the convoys attracts attention and they may be vulnerable to sabotage."

The Weapons Storage and Security System allows to store the weapons underneath the aircraft within hardened aircraft shelters. This increases the weapons survivability in case of an attack. The WS3 consists of several components: The vaults themselves, sensors, data-transmission, consoles and monitors and voice communications. They allow for remotely controlling weapon safety.

The main contractor for the construction program is Bechtel National Inc. from the United States; Mannesmann Anlagenbau of Duesseldorf, Germany, holds the major subcontract for building the mechanical parts for the system.

B-61 and WE-177 bombs

nuclear B-61 free fall bomb is the only type of U.S. tactical nuclear weapons still deployed on European soil. 11 versions of this bomb have been developed and/or produced for use in either tactical or strategic roles. Deployments in Europe are believed to be limited to the more modern tactical versions containing advanced safety features such as Insensitive High Explosives and advanced Permissive Action Links. Models B-61-3 and B-61-4 have been deployed to Europe during the 1980s. Since June 1990 the B-61-10, sometimes also called B-61-4/10, which is a re-converted W85-Pershing-II warhead, has been in production. It is not known, whether the current U.S. posture in Europe consists solely of B-61-10s or whether there are still elder B-61 bombs deployed.

The B-61 is said to be of great tactical flexibility, since the yield as well as the time and type of detonation can be chosen in flight. The weapon can be used by aircraft flying in altitudes as low as 15 meters. The bombs are 3,61 meter long and do have a diameter of 0.34 meters. They can be deployed by a variety of dual-capable aircraft. In Europe F-16s, F-15Es and Tornados are among the aircraft in active inventories certified to carry this weapon.

A new version of the B61, the B61 „mod 11", has been developed in secrecy over the last couple of years - despite a pledge by the Clinton administration that no new types of nuclear weapons are under development in the United States. It was planned to put the B61-11 into service by late 1996 or early 1997. The B61-11 is an earth-penetrating weapon, supposed to replace the old, 9-megaton B53. It is said to be derived from the B61-7, which is a strategic bomb. „Bunkerbusting" or earth-penetrating weapons have been supported because they can play a unique role in striking against deeply buried underground targets especially within the context of controversial counterproliferation-scenarios such as attacking Libya's underground facilities at Tarhunah said to contain a chemical weapons factory. It is unknown whether the new B61-11 is or will be deployed in Europe. Since the weapons main purpose is to replace a strategic nuclear bomb, deployment in Europe is assumed to be relatively unlikely.

Much less is known about the British WE-177 free fall bomb. It was developed during the 1960s, possibly making use of the technology from the US B-57 bomb. Production took place between the mid-1960s and the late 1970s or even early 1980s. Since 1982, the Royal Air Force uses WE 177As with its Tornado aircraft. The yield for the WE 177A is not known. It estimated to be 100-400 kt. Concerns about inadequate and old safety features of these weapons may have influenced the British government's decision to retire these weapons early. On April 4, 1995, it was announced, that all WE 177s will be taken out of service by 1998. There are unconfirmed rumors that by late 1996 all WE 177s have been redeployed to Britain.

Annex A

NATO's 1996 Nuclear Weapons Storage System




Date Completed


Buechel AB




GAF operated base

Memmingen AB




GAF operated base, no weapons currently stored

Noervenich AB




GAF operated base; no weapons currently stored

Ramstein AB




USAF operated base

Brueggen AB




RAF operated base

Kleine Brogel AB




BEAF operated base

Volkel AB




NLAF operated base

RAF Lakenheath




USAF operated base

RAF Marham




RAF operated base

Interim Total by 1995




Aviano AB




USAF operated base

Ghedi-Torre AB



not completed

IAF operated base

Araxos AB



not completed

GRAF operated base

Incirlik AB



not completed

TR/USAF operated base

Murted AB Akinci



not completed

TRAF operated base

Balikesir AB



not completed

TRAF operated base





* planning figures as of 1987, exceeding the total of 208, planned today. It is not known, which bases have been affected by SLOWPIG reductions, but it is most likely that smaller numbers of vaults have been built in Aviano and/or Incirlik. It is unlikely that Balikesir and Murted AB will host nuclear weapons during peacetime. Ghedi-Torre, Araxos and Incirlik might host nuclear weapons once completed since they are with the one national unit in each country operating DCA under a POC that should be maintained fully ready and capable to conduct nuclear missions.

Sources: USAF Electronic Systems Center: Press Release, Hanscom, 18.7.1995

USAF Electronic Systems Center: Communication to BASIC, 20.11.1996

US Congress, House Defense Appropriations Subcommittee,

DoD Appropriations for FY 1987, Part 5, p.216

US Congress, House Defense Appropriations Subcommittee,

DoD Appropriations for FY 1990, part 7, p.479

Institut für Internationale Politik: Die Atomare Planung der NATO nach dem

Ende des Kalten Krieges, Wuppertal, 1990

This report was written by

Otfried Nassauer, Director, Berlin
Information-center for Transatlantic
Security (BITS)

Oliver Meier, Senior Analyst, Berlin
Information-center for Transatlantic
Security (BITS)

Nicola Butler, Analyst, British American
Security Information Council (BASIC)

Stephen Young, Senior Analyst, British
American Security Information Council

Published by the Berlin Information-center for Transatlantic Security (BITS). All rights reserved.

February 1997


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