Nuclear weapons at a glance: United States - UK Parliament
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
BRIEFING PAPER
Number 9082, 11 December 2020
Nuclear weapons at a By Claire Mills
glance: United States
Contents:
1. Nuclear status
2. Nuclear Policy
3. Nuclear arms control
agreements
4. Capabilities
5. Modernisation of US nuclear
capabilities
www.parliament.uk/commons-library | intranet.parliament.uk/commons-library | papers@parliament.uk | @commonslibrary2 Nuclear weapons at a glance: United States
Contents
Summary 3
1. Nuclear status 4
2. Nuclear Policy 5
2.1 2018 Nuclear Posture Review 5
2.2 Declaratory policy 6
2.3 A change of nuclear policy under Biden? 7
3. Nuclear arms control agreements 8
3.1 Bilateral arms control 8
3.2 Other nuclear-related agreements 9
4. Capabilities 12
4.1 Stockpile 12
4.2 Fissile material 12
4.3 US Navy 12
4.4 US Air Force – Global Strike Command 13
US nuclear forces in NATO countries 13
5. Modernisation of US nuclear capabilities 15
5.1 Affordability 17
Cover page image copyright: Atomic bomb mushroom cloud explosion. No copyright
required3 Commons Library Briefing, 11 December 2020
Summary
The 2018 Nuclear Posture Review (NPR) sets out the current nuclear
Under a Biden
policies of the US Administration. Deterrence, and not disarmament, is administration, a return
the overriding message of the Trump administration’s NPR. It marks a to the nuclear polices of
significant departure from key nuclear policies under the Obama the Obama era is
administration that sought to lower the reliance on nuclear weapons considered likely.
and embrace non-proliferation and disarmament.
Despite considerable progress in bilateral arms control since the 1970s,
the United States still deploys an extensive nuclear force and is in the
process of modernising and replacing its nuclear capabilities.
• As of January 2020, the total US nuclear stockpile was estimated
at 5,800 warheads. Of those 3,800 are operational (strategic,
non-strategic and reserve), including 1,372 deployed strategic
nuclear warheads. A further 2,000 warheads are awaiting
dismantlement.
• Under the US-Russian new START treaty, the number of deployed
strategic warheads must not exceed 1,550. New START expires in
February 2021, unless an extension to the treaty is agreed.
• Non-strategic warheads are not currently subject to any arms
control limitations.
• US forces are organised on the nuclear triad principle.
• A portion of nuclear forces are maintained on day-to-day alert
and the US adopts the practice of open ocean targeting of its
strategic nuclear forces.
• The US retains a first-use option.
The US is undertaking an extensive modernisation programme across
every element of the nuclear triad. That recapitalisation project is
estimated to cost $494 billion over the next decade, and at least $1.2
trillion over the next 30 years.
Under a Biden administration, a return to the nuclear policies of the
Obama era is considered likely. President-elect Biden has already
questioned the US’ level of “excessive” nuclear spend, which has led
many commentators to begin speculating on possible future cuts to the
nuclear modernisation programme.
This short paper is intended as an introduction to the United States’
nuclear weapons policies and programmes. It is part of a series of
country profiles which are available on the House of Commons Library
website.4 Nuclear weapons at a glance: United States
1. Nuclear status
The United States conducted its first nuclear test in July 1945 and is the
only country to have used nuclear weapons in conflict, when it dropped
atomic bombs on the Japanese cities of Hiroshima and Nagasaki in
August 1945.
Under the Nuclear Non-Proliferation Treaty (NPT) a nuclear weapon
state is defined as one that manufactured and exploded a nuclear
weapon, or other nuclear explosive device, prior to 1 January 1967.
Alongside the other permanent members of the UN Security Council
(the P5), the US is, therefore, one of the five officially recognised nuclear
weapon states under the NPT.5 Commons Library Briefing, 11 December 2020
2. Nuclear Policy
2.1 2018 Nuclear Posture Review
The current nuclear policies of the US Administration are set out in the
2018 Nuclear Posture Review. 1
Deterrence, and not disarmament, is the overriding message of the
Trump administration’s NPR. It marks a significant departure from key
nuclear policies under the Obama administration that sought to lower
the reliance on nuclear weapons and embrace non-proliferation and
disarmament. 2
The NPR acknowledges the re-emergence of long term “great power”
competition as a defining feature of the strategic environment. Russia
and China are central to the NPR’s strategic threat assessment, along
with the threats posed by the nuclear ambitions of North Korea and Iran
and by nuclear terrorism.
To that end, the focus of the NPR is on deterrence, albeit through a new
lens. As the US Deputy Secretary of Energy noted in a Pentagon press
conference:
Over the past decade, while the United States has led the world in
[nuclear] reductions, every one of our potential nuclear adversaries
has been pursuing the exact opposite strategy.
These powers are increasing the numbers and types of nuclear
weapons in their arsenal, with some of them establishing
doctrines of limited and coercive nuclear use […]
The United States needs to respond by achieving new and
effective balance in our deterrent capabilities. 3
The NPR therefore reiterates the view that the nuclear triad supported
by a robust command and control and communications (C3) system, is
the most cost-effective means of ensuring strategic nuclear deterrence.
Consequently, it re-affirms the US’ commitment to the nuclear
modernisation programmes already underway across each leg of the
triad (see below), and to the modernisation of nuclear C3. The review
also committed to the major recapitalisation of the nuclear complex in
order to “ensure the capability to design, produce, and maintain nuclear
weapons”. 4
1
A Nuclear Posture Review (NPR) is a comprehensive examination, led by the US
Department of Defense, of US nuclear policy, strategy, capabilities and force
posture. It is an opportunity for the US administration to set out its rationale for
nuclear weapons, and its overall aspirations with respect to nuclear policy, within the
context of its overall national security strategy. Congressional support for the
conclusions of an NPR is demonstrated through its allocation of resources for
relevant programmes.
2
The conclusions of the 2010 Nuclear Posture Review is briefly summarised in
President Trump: the nuclear question, House of Commons Library, 22 October
2018
3
US Department of Defense, News Briefing on the 2018 Nuclear Posture Review, 2
February 2018
4
ibid6 Nuclear weapons at a glance: United States
However, the NPR also emphasised the need to maintain flexibility in
any nuclear response, given “the range of adversaries, their capabilities
and strategic objectives”, noting that a “one size fits all” approach no “Four successive
longer applies. 5 Republican and
Democratic
In a major departure from the 2010 review, the 2018 NPR therefore administrations
stated the intention of the Department of Defence (DoD) to introduce since the end of the
new “flexible”, non-strategic, options into the US nuclear inventory, in Cold War had
order to provide tailored deterrence. sought to reduce
the role and number
Specifically, the NPR recommended lowering the yield of some existing
of nuclear weapons
submarine-launched ballistic missile warheads, and re-introducing
in US national
nuclear capable, sea-launched cruise missiles. 6 However, the Pentagon security strategy.
sought to emphasise that neither recommendation required the This NPR makes a
development of new nuclear warheads. Nor would they result in an dangerous and
increase to the nuclear stockpile, thereby remaining compliant with all unjustified U-
of the US’ arms control treaty obligations. 7 The NPR referred to them as turn…”
“modest enhancements to current capabilities”. 8
Lynn Rusten, Nuclear
However, many argued that, while the introduction of lower-yield Threat Initiative
warheads and new cruise missiles may not be a quantitative increase in
the size of the US nuclear arsenal, it represented a qualitative increase in
capability and therefore undermined any overtures towards
disarmament.
2.2 Declaratory policy
The US has never adopted a “no first use” policy.
The 2018 NPR reiterates the overarching approach that nuclear
weapons will only be used in “the most extreme circumstances to
defend the vital interests of the United States, its allies and partners”. 9
What is defined as an “extreme circumstance” differs significantly,
however, from the previous NPR. The Trump NPR expands the definition
of “extreme circumstances” to include significant non- nuclear strategic
attacks, including cyber, on critical infrastructure and civilian
populations, and attacks on US or allied nuclear forces, including
command and control and warning and attack assessment capabilities.
The NPR also places a caveat on the security assurances extended to
those non-nuclear weapon states that are party to the Nuclear Non-
Proliferation Treaty, and in compliance with their non-proliferation
obligations. Under the new NPR the US “reserves the right to make any
adjustment in the assurance that may be warranted by the evolution
5
US Department of Defense, Nuclear Posture Review Fact Sheet: Nuclear Deterrence
in the 21st Century, February 2018
6
Prior to 2010 the US Navy deployed the nuclear Tomahawk land-attack cruise missile
(TLAM/N) aboard some of its attack submarines. Its withdrawal from service was
announced in the 2010 Nuclear Posture Review.
7
US Department of Defense, News Briefing on the 2018 Nuclear Posture Review, 2
February 2018
8
US Department of Defense, 2018 Nuclear Posture Review Factsheet, February 2018
9
US Nuclear Posture Review, p.217 Commons Library Briefing, 11 December 2020
and proliferation of non-nuclear strategic attack technologies and US
capabilities to counter that threat”. 10
This change in language has caused concern among experts who have
argued that it could have the effect of lowering the bar for first use of
nuclear weapons and that threatening such use in response to
cyberattacks or attacks on nuclear C3 would lack credibility.
The Trump administration has, however, argued that its stance merely
clarifies existing policies, rather than marking a radical departure from
previous nuclear policies. 11
A portion of the US’ nuclear forces are maintained on day-to-day alert.
The US also adopts the practice of open ocean targeting of its strategic
nuclear forces.
2.3 A change of nuclear policy under Biden?
Under a Biden administration a return to the nuclear policies of the
Obama era is considered likely.
In the past President-elect Biden has expressed the belief that nuclear
“The sole purpose of
weapons should play a smaller role in US defence strategy and that a the US nuclear
nuclear-free world should be the ultimate goal. He opposed the decision arsenal should be
in the 2018 NPR to introduce lower yield, non-strategic nuclear options deterring – and, if
into the nuclear arsenal and has expressed the belief that current US necessary, retaliating
nuclear spending is excessive. against – a nuclear
attack.”
Biden has also expressed support for extending the New START treaty
with Russia, re-engaging with the Joint Comprehensive Plan of Action President-elect Joe
with Iran, and pursuing “principled diplomacy” with North Korea. He Biden, “Why America
also supports bringing the CTBT into force, which would require must lead again”,
ratification by the US Senate (see below), while also suggesting that the Foreign Affairs,
March/April 2020
US’ first-use policy should be reviewed. 12
However, as James Acton at the Carnegie Endowment for International
Peace has observed:
Biden’s instincts on nuclear weapons are more liberal than those
of much of the Democratic Party’s defense establishment. But that
doesn’t necessarily mean he would fundamentally change US
nuclear policy. In practice, there are often pressures to continue
the status quo. 13
Any changes to US nuclear policy will be set out in a new Nuclear
Posture Review. There is no official timeframe for when an NPR must
take place, although NPR’s have been conducted by each of the four
previous US administrations at the start of their term in office. 14
10
US Nuclear Posture Review, p.21
11
US Department of Defense, News Briefing on the 2018 Nuclear Posture Review, 2
February 2018
12
Council for a Livable World, updated October 2020
13
“Biden would push for less US reliance on nukes for defense”, Associated Press, 21
September 2020
14
Bill Clinton – September 1994, George W. Bush – December 2001, Barack Obama –
April 2010, Donald Trump – February 2018.8 Nuclear weapons at a glance: United States
3. Nuclear arms control
agreements
3.1 Bilateral arms control
After the Cuban Missile Crisis, and throughout the 1960s, there was
mounting concern about the rapid expansion in the number of nuclear
warheads and delivery systems. In response, bilateral talks aimed at
restricting the nuclear arsenals of the Soviet Union and the US began.
Over the decades that followed, a series of arms control regimes
emerged.
A history of these bilateral arms control agreements is available in:
Nuclear weapons: disarmament and non-proliferation regimes, House of
Commons Library, June 2016
Of those agreements only the New START treaty, concluded in 2010,
remains in force. The US officially withdrew from the Intermediate-
Range Nuclear Forces (INF) treaty on 2 August 2019.
Box 1: Provisions of New START
Under the terms of New START the US and Russia committed to:
• A limit of 1,550 strategic operationally deployable warheads
• A combined limit of 800 deployed and non-deployed intercontinental ballistic missile (ICBM)
launchers, submarine launched ballistic missile (SLBM) launchers and heavy bombers equipped
for nuclear armaments.
The treaty also established a verification regime that combines various elements of the original START
verification regime and measures that are tailored to the current treaty.
The treaty will remain in force until February 2021, unless it is
superseded by a subsequent agreement, or extended by Presidential
agreement for no more than five years.
Over the last six months, negotiations on New START have failed to
produce any agreement on a potential extension. Prior to the US
Presidential election in November 2020, both sides had signalled a
willingness to reach a deal involving an extension of the treaty for one
year and a freeze on all US and Russian nuclear warheads. However,
negotiators failed to agree the specific terms of the deal.
The fate of the treaty is now considered to lie in the hands of President
Putin and the incoming Biden administration. While President-elect
Biden has expressed support for the treaty’s extension, he will have only
two weeks after inauguration to agree a deal. 15
15
New START expires on 5 February 2021. For background see Prospects for US-
Russian nuclear arms control, House of Commons Library, July 20209 Commons Library Briefing, 11 December 2020
3.2 Other nuclear-related agreements
American nuclear assets contribute to the NATO nuclear umbrella and
US tactical nuclear weapons are based in a number of European
countries (see below). 16
In Asia and the Middle East, the US has maintained extended deterrence
through a series of bilateral arrangements, a forward military presence
and security guarantees. 17
Nuclear Non-Proliferation Treaty. Article VI, NPT
As a State Party to the NPT, the US has a legal obligation to pursue
disarmament under Article VI of that treaty. Each of the Parties to
the Treaty undertakes
Comprehensive Test Ban Treaty to pursue negotiations
in good faith on
The US signed the Comprehensive Test Ban Treaty in 1996, but effective
Congress is yet to ratify it. 18 The Senate rejected ratification in 1999 and measures relating to
despite a commitment in the 2010 NPR to seek ratification of the treaty, cessation of the
the US administration failed to bring the matter before Congress before nuclear arms race at an
President Obama left office in January 2017. early date and to
nuclear disarmament,
While the 2018 NPR confirmed the US’ intention to maintain its and on a treaty on
moratorium on nuclear testing, ratification of the Comprehensive Test general and complete
Ban Treaty was no longer a policy objective under the Trump disarmament
administration. Instead the NPR takes an open-ended approach: under strict and
The United States will not resume nuclear explosive testing unless effective international
necessary to ensure the safety and effectiveness of the U.S. control.
nuclear arsenal and calls on all states possessing nuclear weapons
to declare or maintain a moratorium on nuclear testing. 19
However, the possibility of the US resuming explosive nuclear testing
was reportedly discussed by senior Trump administration officials in May
2020. Those discussions were in response to allegations put forward by
the US State Department that Russia and China had conducted nuclear
tests “inconsistent with the zero-yield standard”. 20 Both countries have
denied the allegation.
16
Belgium, Germany, Italy, Netherlands and Turkey. Some commentators consider
those states to be nuclear states by virtue of the fact that US nuclear weapons are
based on their soil. See “US tactical nuclear weapons in Europe”, Bulletin of the
Atomic Scientists, 2011. US nuclear weapons were withdrawn from the UK in 2008.
17
The concept of extended deterrence is an important one, particularly for countries
such as Japan which has chosen to forego the option of developing its own nuclear
capability in return for the protection provided by the US nuclear umbrella. A
number of analysts have suggested that abandoning extended deterrence could
encourage proliferation as several states could seek to develop their own nuclear
weapons capability as an alternative.
18
The CTBT will only enter into force 180 days after ratification by the five nuclear-
weapon states and a further 39 non-nuclear weapon states that were identified at
the time the treaty was negotiated as possessing either civilian nuclear power
reactors and/or nuclear research reactors. Collectively these 44 states are referred to
as Annex 2 states. Eight annex 2 states have yet to ratify the treaty: the US, China,
Israel, India, Pakistan, North Korea, Egypt and Iran.
19
US Nuclear Posture Review, p.72
20
US State Department, 2020 Adherence to and Compliance with Arms Control,
Nonproliferation and Disarmament Agreements and Commitments (Compliance
Report)10 Nuclear weapons at a glance: United States
Those discussions have not resulted in a change of US policy, but they
have been met with widespread criticism from US lawmakers and the
international disarmament community alike. In June 2020 a number of
prominent US scientists wrote a letter to the Senate Majority Leader,
Mitch McConnell, urging Congress to prevent the resumption of nuclear
testing, arguing that “nuclear explosive testing of any US warhead
would serve no technical or military purpose”.
The current administration’s openness to discussing the idea of testing
therefore raised concerns that it could withdraw from, or “un-sign”, the
CTBT. 21 However, President-elect Biden has expressed support for the
CTBT and considers the US to have already gained “adequate data from
decades of tests”. 22 It also raises the possibility that his administration
may pursue Senate ratification of the CTBT at some point in the future.
Fissile Material Cut-Off Treaty
At the 2018 NPT Preparatory Committee, the US administration
expressed continued US support for the commencement of negotiations
on a fissile material cut-off treaty. 23
Open Skies Treaty
In May 2020 the US announced its intention to withdraw from the
Open Skies Treaty. 24 Although not concerned with direct limitations on
nuclear stockpiles, delivery systems or materials, the treaty established
confidence building measures in relation to each State Parties military
capabilities, including nuclear assets.
The US justified its decision on the grounds that Russia had been
violating the agreement and stated that it may reverse its decision if
Russia returned to compliance.
However, the Trump administration confirmed the US’ withdrawal from
the treaty on 22 November 2020. National Security Adviser, Robert
O’Brien said the decision to withdraw was part of an effort to “put
America first by withdrawing us from outdated treaties and agreements
that have benefitted our adversaries at the expense of our national
security”. 25
The withdrawal has been viewed as the latest blow to the international
arms control architecture.
21
The Vienna Convention provides that between signature and ratification of a treaty
a state has an obligation not to act in a manner that is inconsistent with the
agreement. “Un-signing” the CTBT was previously considered by the George W.
Bush administration. See David Scott, “Presidential power to ‘un-sign’ treaties”,
University of Chicago Law Review, 2002
22
Council for a Livable World, updated October 2020
23
An FMCT is a proposed international agreement that would prohibit the production
of the two main components of nuclear weapons: highly enriched uranium (HEU)
and plutonium. Efforts to begin negotiations have in place since the early 1990s.
24
Signed in 1992 and entered into force in 2002, the treaty permits each State Party
to conduct short notice, unarmed, observation flights over the territories of other
State Parties in order to collect data on military forces and activities. All imagery
collected is then shared with the other State Parties.
25
National Security Council Twitter account, 22 November 202011 Commons Library Briefing, 11 December 2020 Treaty on the Prohibition of Nuclear Weapons The United States Administration has not signed the Treaty on the Prohibition of Nuclear Weapons which was adopted in 2017. The treaty received its 50th State ratification on 24 October 2020. It will now enter into force in January 2021.
12 Nuclear weapons at a glance: United States
4. Capabilities
Nuclear deterrence is one of the five missions under the responsibility of
US Strategic Command. Like Russia, China, and more recently India, the
US operates a nuclear triad of sea, land and air-based systems.
4.1 Stockpile
As of January 2020, SIPRI estimated the total US nuclear stockpile at
5,800 warheads, of which:
• 3,800 are active/operational warheads (strategic, non-strategic
and reserve)
• 2,000 are retired and awaiting dismantlement.
The most recent data exchanged between the US and Russia under the
terms of the New START agreement showed that of those 3,800
operational US warheads 1,457 were deployed strategic nuclear
warheads (below the ceiling agreed). 26 The US also has 500 non-
strategic warheads in its inventory. Approximately 150 of those
warheads are thought to be deployed in Europe. 27
In 2019 the Trump administration stopped publicly disclosing the size of
the US nuclear stockpile.
4.2 Fissile material
The US no longer produces fissile material for weapons purposes,
although it does retain a stockpile. 28 The latest figures from the
International Panel on Fissile Materials suggests that the US has 565
tons of highly enriched uranium (HEU) and 79.7 tons of plutonium for
weapons purposes. 29
4.3 US Navy
The Navy has 14 Ohio class ballistic missile submarines (SSBN) equipped
with up to 20 Trident II D5 SLBM. 30 Two of those SSBN are in refit at
any one time, while the remaining 12 are available for deployment. The
US has operated a posture of continuous at-sea deterrence since 1960.
In total, those 12 operational SSBN are capable of deploying 240 trident
missiles. Each one of those missiles can be configured with up to 12
26
US Department of State data as of 1 December 2020
27
Kristensen and Norris, “Worldwide deployments of nuclear weapons, 2017, Bulletin
of the Atomic Scientists, 31 August 2017
28
The US halted the production of HEU for weapons in 1964 and ceased plutonium
processing for weapons in 1992.
29
The amount of HEU needed to make a nuclear weapon varies with the degree of
enrichment and the sophistication of the weapon design. In general, the higher the
enrichment level and greater sophistication, the less HEU is needed to make a bomb.
Plutonium-based nuclear weapons only work as implosion weapons, with more
sophisticated weapons using less plutonium. The International Panel on Fissile
materials estimates a second generation boosted warhead would require 12kg of
HEU or 4-5kg of plutonium (Global Fissile Materials Report 2015)
30
The Ohio class is capable of deploying with 24 missiles. Under the terms of New
START the actual number of deployed missiles was reduced to 20 in 2016.13 Commons Library Briefing, 11 December 2020
warheads, although in practice each missile is thought to deploy with 4
or 5 warheads apiece.
In late 2019 the Navy started to deploy a new low-yield warhead (the
W76-2) on some of its SSBN, as promised in the 2018 NPR.
A service-life extension programme for the Trident II D5 missile will keep
the missile in service until at least 2042. A programme to replace the
Ohio class SSBN is currently underway (see below).
4.4 US Air Force – Global Strike Command
Ground-launched
The US Air Force fields an estimated 400 Minuteman III ground-
launched ICBM, which has a range of approximately 13,000km.
Under the 2010 NPR the Obama administration announced plans to de-
MIRV 31 existing missiles, with each missile now carrying a single
warhead. 32 That process was completed in June 2014. Under New
START 50 ICBM have been removed from their silos, although they are
expected to be kept in reserve. 33
A series of service-life extension programmes for the Minuteman III will
retain the ICBM in service until 2030.
Air-launched capability
The Air Force also operates a fleet of 66 bombers, which are dual-
capable and therefore able to deploy with both nuclear and
conventional munitions. 34 Of those, 20 are B2-A Spirit bombers and 46
are B-52H Stratofortress bombers. The B2-A carries up to 16 nuclear-
armed gravity bombs, while the B-52H is capable of carrying 20 air-
launched cruise missiles.
In addition, the US also deploys several fighter aircraft in a dual-use
tactical role. The F-15 and F-16, carrying the B-61 gravity bomb have
been the cornerstone of this force. In the future this capability will be
replaced by the Joint Strike Fighter and an upgraded gravity bomb: the
B61-12 (see below).
US nuclear forces in NATO countries
As outlined above, the US has tactical nuclear forces deployed at six
bases in five NATO countries: Belgium, Germany, Italy, Netherlands and
Turkey. 35 All of those countries are parties to the NPT and have signed
and ratified the CTBT. US nuclear weapons were removed from Greece
in 2001 and from the UK in 2008. In 2019 the US was reported to be
reviewing the basing of its nuclear weapons in Turkey, given recent
31
MIRV – multiple independently targetable re-entry vehicle, meaning a missile is
capable of carrying multiple warheads.
32
The missiles will remain MIRV-capable and warheads are expected to remain in
storage should it become necessary.
33
“US nuclear forces 2015”, Bulletin of the Atomic Scientists, 2015
34
No more than 60 bombers are deployed at any one time.
35
Aviano and Ghedi in Italy, Büchel in Germany, Incirlik in Turkey, Kleine Brogel in
Belgium and Volkel in the Netherlands. Approximately one third of the weapons in
Europe are reportedly based at Incirlik.14 Nuclear weapons at a glance: United States
tensions with the country. 36 Several media reports speculated that the
US could relocate its nuclear assets to the US naval facility at Souda Bay
in Crete.
Those nuclear forces currently comprise an estimated 150 B-61 gravity
bombs 37 capable of being deployed on US F-15, F-16 aircraft; Belgian,
Dutch and Turkish F-16 aircraft and German and Italian Tornados. The
US maintains “absolute control and custody of the associated nuclear
weapons”. 38 It has been noted that under a programme, referred to as
Snowcat (support of nuclear operations with conventional air tactics), all
NATO countries participate in NATO’s nuclear mission even if they do
not have nuclear weapons stationed on their territory or have aircraft
tasked with a nuclear role. 39
At the NATO Heads of State and Government Summit in Warsaw in July
2016 NATO leaders reaffirmed NATO’s nuclear status, and on the
subject of tactical nuclear weapons in Europe, stated:
NATO's nuclear deterrence posture also relies, in part, on United
States’ nuclear weapons forward-deployed in Europe and on
capabilities and infrastructure provided by Allies concerned. These
Allies will ensure that all components of NATO's nuclear deterrent
remain safe, secure, and effective. That requires sustained
leadership focus and institutional excellence for the nuclear
deterrence mission and planning guidance aligned with 21st
century requirements. The Alliance will ensure the broadest
possible participation of Allies concerned in their agreed nuclear
burden-sharing arrangements. 40
36
See “Concern grows about US weapons in Turkey”, Arms Control Today, November
2019 and “Urgent: move US nuclear weapons out of Turkey”, Federation of
American Scientists Blog, 16 October 2019
37
At the height of the Cold War the US had 7,300 tactical nuclear weapons deployed
in Europe. Since the 1970s that number has been steadily shrinking. In 1986 the US
withdrew nearly 2,000 weapons, followed by 3,000 between 1991 and 1993. By
2001 the US is estimated to have had 480 tactical nuclear weapons in Europe, which
was subsequently halved to 200 by 2007 (See Norris and Kristensen, “US tactical
nuclear weapons in Europe”, Bulletin of the Atomic Scientists, 2011)
38
NATO website: NATO’s nuclear deterrence policy and forces
39
Norris and Kristensen, “US tactical nuclear weapons in Europe”, Bulletin of the
Atomic Scientists, 2011
40
NATO Warsaw Summit Communiqué, 9 July 2016, para.5315 Commons Library Briefing, 11 December 2020
5. Modernisation of US nuclear
capabilities
The last time the United States undertook a major modernisation of its
nuclear arsenal was in the 1980s. Most of those systems are now
nearing the end of their service lives.
Consequently, the Obama administration began an extensive nuclear
Over the next 30
modernisation programme across all three elements of the nuclear triad. years, the US
In 2014 it was estimated that the cost of maintaining, modernising and nuclear
replacing the triad, over the next 30 years, could be in the region of modernisation
$600 billion to $1 trillion. 41 Such expenditure was likened to “spending programme is
for procurement of new strategic systems in the 1980s under President forecast to cost at
Ronald Reagan”. 42 least $1.2 trillion.
Not only has the Trump administration continued on that modernisation
path, it has expanded this agenda. An estimate published by the
Congressional Budget Office in 2019 suggested that the nuclear
programme is expected to cost $494 billion up to 2028. Over the next
30 years, the whole modernisation programme is now expected to cost
at least $1.2 trillion. 43
Between 2021 and 2025 projected spending on the nuclear arsenal is
estimated to consume 6-6.8 per cent of total national defence
spending. 44
The Pentagon’s modernisation priorities cover all three legs of the
nuclear triad:
• A new class of SSBN (the Columbia class submarine) which will
replace the current Ohio class from 2031. Twelve new SSBN are
planned and will be equipped with 16 missiles tubes, as opposed
to the current 24 (although only 20 are operational). The
estimated cost of the total programme is $128 billion (including
research and development), or an average of $10.6 billion per
submarine). It will be the Pentagon’s third largest procurement
programme and is expected to consume 40 per cent of the US
Navy’s shipbuilding budget. On 9 December 2020, the Pentagon
published its 30-year shipbuilding plan in which fully funding the
Columbia class programme was identified as the main priority.
The Columbia class will initially be deployed with the upgraded
Trident II D5 missile. That missile will eventually be replaced with a
new SLBM. Cost effectiveness studies on a replacement missile are
expected to begin in late 2020.
• In 2019 the Navy also began an analysis of alternatives study for
the new nuclear-armed sea-launched cruise missile identified in
41
Ensuring a strong US defense for the future, National Defense Panel Review of the
2014 Quadrennial Defense Review, July 2014
42
The Trillion Dollar Nuclear Triad, Center for Nonproliferation Studies, January 2014
43
Upper end estimates have placed the total cost of the modernisation programme at
$1.7 trillion once inflation is taken into account (see: “CBO: nuclear arsenal to cost
$1.2 trillion”, Arms Control Today, December 2017)
44
“Surging US nuclear weapons budget a growing danger”, Arms Control Association
Issue Brief, 19 March 202016 Nuclear weapons at a glance: United States
the 2018 NPR. If funded by Congress, the new missile could be
deployed on attack submarines by the end of the 2020s.
• A new long-range strike bomber (B-21) for deployment in the
mid-2020s. Current expectations are for a fleet of at least 100
aircraft, although the final total may be higher. Independent
estimates have suggested the programme could cost at least $110
billion. 45
The new bomber will be equipped with the new B61-12 guided
stand-off nuclear gravity bomb, which is scheduled to begin
delivery in 2022 and completed in 2025, at a cost of $8-9 billion.
It will also be equipped with a new long-range standoff (LRSO)
cruise missile. The US Air Force plans to procure approximately
1,000 LRSO missiles, of which half will be nuclear armed, for
deployment in 2026. The B61-12 will also be deployed in Europe
in the mid-2020s. Initially it will be retrofitted to existing F-15, F-
16 and Tornado aircraft but will eventually arm US F-35 aircraft
once they are deployed. 46
• A next generation ICBM (the Ground Based Strategic Deterrent
programme) which will replace the Minuteman III from 2028. It is
expected to achieve full operational capability in 2036. The new
missile is expected to have greater range that the current
Minuteman, making it possible to target, not only Russia, but also
China, North Korea and Iran from the continental US. Under
current plans replacement of the Minuteman III and rebuilding the
existing infrastructure is expected to cost in the region of $95 -
$140 billion over the next 30 years. 47 It will provide the US with a
nuclear ICBM capability well into the 2070s. There has been
controversy over the Pentagon’s handling of the programme after
Boeing dropped out in July 2019 citing unfair competition. That
decision left Northrop Grumman as the sole bidder. In September
2020 the US Air Force awarded a $13.3 billion manufacturing
contract to the company.
In the past it has been suggested that the Air Force has also been
examining options for the replacement system to be deployed, in
the longer term, on mobile launchers. An article in Arms Control
Today in April 2016 noted that such a development would be
“unprecedented” in US nuclear strategy, noting that the US
examined two mobile ICBM options during the Cold War, both of
which were cancelled before they became operational. The
development of such a system would be expected to cost at least
$80 billion more over the next 50 years than the retention of only
silo-based ICBM. 48 It is unclear whether mobile launchers remain
an option. 49
45
“Trump continues Obama nuclear funding”, Arms Control Today, August 2017
46
The Netherlands, Italy and Belgium are buying the F-35 from the US. The US has
halted delivery of the F-35 to Turkey because of its plans to procure the S-400 air
defence system from Russia. Germany has rejected the F-35 in favour of purchasing
either an upgraded Typhoon or The F-18.
47
The initial cost estimate published by the US Air Force in 2015 was $62.3 billion
48
“Air Force seeks mobile ICBM option”, Arms Control Today, April 2016
49
This is discussed in greater detail in Congressional Research Service report US
Strategic Nuclear Forces: Background, Developments and Issues, April 202017 Commons Library Briefing, 11 December 2020
In support of these plans, a number of nuclear warhead programmes
are also underway by the National Nuclear Security Administration. Over
the next five years the NNSA is reportedly planning to request over $81
billion for nuclear weapons activities. 50 The programmes it has
underway include:
• the W76-1 life extension programme (LEP) and the W88
Alteration 370 programme, both for the Trident II D5 missile.
• the B61-12 LEP (see above)
• the W80-4 LEP which will provide a warhead for the long-range
stand-off cruise missile programme.
• the IW-1 LEP which is intended to provide an interoperable
warhead for various systems.
• The W87-1 warhead which will arm the ground based strategic
deterrent, replacing the Minuteman III. The projected cost of that
programme is $12.4 billion.
Funding has also been requested in FY2021 for a new W-93 warhead
and its Mk7 re-entry vehicle, which would be deployed on the Trident II
D5 from the mid-2030s. The W-93 will eventually replace the W-76 and
the W-88. The request has come two years ahead of schedule.
At an estimated $14 billion, the W-93 will be the Navy’s third
submarine-launched warhead programme. As such it has been labelled
by many analysts as unnecessary. 51 Crucially, however, work on the W-
93 programme will support the UK’s own replacement warhead
programme. 52 In a letter to Congress in April 2020, Defence Secretary
Ben Wallace reportedly urged Congress to support initial spending on
the programme, stating:
Your support to the W93 program in this budget cycle is critical to
the success of our replacement warhead programme and to the
long-term viability of the UK’s nuclear deterrent and therefore,
the future of NATO as a nuclear alliance. 53
His intervention has raised concerns over the independence of the UK’s
nuclear deterrent and the long-term viability of the new replacement
programme if US support is not forthcoming. 54
5.1 Affordability
The affordability of the US nuclear modernisation programme has been
questioned. The cost of several programmes has already been revised
upwards by several billion dollars. The addition of several new
programmes by the Trump administration has also increased costs. In
50
“Surging US nuclear weapons budget a growing danger”, Arms Control Association
Issue Brief, 19 March 2020
51
“Trump team’s case for new nuke cites risks in current arsenal”, Congressional
Quarterly Roll Call, 29 July 2020
52
For further detail on the UK programme see Replacing the UK’s nuclear deterrent:
the long awaited warhead decision, House of Commons Library , June 2020
53
As reported in “UK lobbies US to support controversial new nuclear warheads”, The
Guardian, 1 August 2020
54
See Matthew Harries, Will America help Britain to build a new nuclear warhead?, 22
October 202018 Nuclear weapons at a glance: United States
the mid-2020s spending on all three legs of the nuclear triad is expected
to consume between five and seven per cent of the entire US defence
budget. 55
A number of experts have warned that the programme, as it stands,
cannot be sustained without significant and sustained increases to the “The administration’s
excessive strategy to
defence budget and/or cuts to conventional military programmes.
replace nearly the
Former US Defense Secretary, James Mattis, told the House Armed entire US nuclear
Services Committee in June 2017 that the cost to sustain and upgrade arsenal at roughly the
the US nuclear arsenal is affordable “if appropriately prioritized”. 56 That same time is a ticking
sentiment was echoed in the 2018 NPR. In February 2020, however, budget time bomb…”
Admiral Charles Richard, Head of US Strategic Command, said:
Arms Control
I am concerned that the oft-repeated message of the need to Association, March
modernize and recapitalize has lost its impact and that collectively 2020
we have underestimated the risks associated with such a complex
and time-constrained modernization and recapitalization effort. 57
And the US defence budget is likely to face further pressure over the
next few years because of the impact of emergency spending to tackle
Covid-19. In the view of Kingston Reif, “the response to the virus is
likely to exacerbate the affordability and execution challenges
confronting the administration’s nuclear spending plans”. 58 William J.
Perry, US Defense Secretary under President Bill Clinton, has argued:
Our nation faces major security challenges, including a global
pandemic that has killed almost 200,000 Americans, and we
shouldn’t spend our limited resources on new nuclear weapons
that we don’t need and make us less safe. 59
President-elect Joe Biden has also questioned the US’ level of nuclear
spend, calling it “excessive”. 60 That comment has led many to begin
speculating whether the next administration may find ways to scale
back the nuclear modernisation programme.
Box 2: Suggested reading
• Senate Armed Services Committee, Matters relating to the budget of the National Nuclear
Security Administration, 17 September 2020
• “Surging US nuclear weapons budget a growing danger”, Arms Control Association Issue Brief,
19 March 2020
• Statement of the Commander, United States Strategic Command before the Senate Committee
on Armed Services, February 2020
• US strategic nuclear forces: background, developments and issues, US Congressional Research
Service, 27 April 2020
55
See “Can the US afford to modernise its nukes?”, Jane’s Defence Weekly, 12
August 2015 and “The US nuclear weapons spending binge”, Arms Control Today,
December 2015
56
“Trump continues Obama nuclear funding”, Arms Control Today, August 2017
57
Senate Committee on the Armed Services, Transcript of Hearing, 13 February 2020
58
“Debating nuclear spending in the age of coronavirus”, Bulletin of the Atomic
Scientists, 10 June 2020
59
“Northrop Grumman wins $13.3 billion contract to replace US ballistic missiles”, The
Washington Post, 9 September 2020
60
Council for a Livable World, updated October 202019 Commons Library Briefing, 11 December 2020
• Nonstrategic nuclear weapons, US Congressional Research Service, 4 May 2020
• Kristensen and Korda, Nuclear Notebook: United States nuclear forces, 2020
• World Nuclear Forces, SIPRI Yearbook 2020
• US Department of Defense, Joint Publication 3-72, Nuclear Operations, June 2019About the Library
The House of Commons Library research service provides MPs and their staff
with the impartial briefing and evidence base they need to do their work in
scrutinising Government, proposing legislation, and supporting constituents.
As well as providing MPs with a confidential service we publish open briefing
papers, which are available on the Parliament website.
Every effort is made to ensure that the information contained in these publicly
available research briefings is correct at the time of publication. Readers should
be aware however that briefings are not necessarily updated or otherwise
amended to reflect subsequent changes.
If you have any comments on our briefings please email papers@parliament.uk.
Authors are available to discuss the content of this briefing only with Members
and their staff.
If you have any general questions about the work of the House of Commons
you can email hcenquiries@parliament.uk.
Disclaimer
This information is provided to Members of Parliament in support of their
parliamentary duties. It is a general briefing only and should not be relied on as
a substitute for specific advice. The House of Commons or the author(s) shall
not be liable for any errors or omissions, or for any loss or damage of any kind
arising from its use, and may remove, vary or amend any information at any
time without prior notice.
The House of Commons accepts no responsibility for any references or links to,
BRIEFING PAPER or the content of, information maintained by third parties. This information is
Number 9082
provided subject to the conditions of the Open Parliament Licence.
11 December 2020You can also read
