Future Nuclear Weapons Policies

Future nuclear weapon policies
James M. Acton
[email protected]
(Some) elements of nuclear posture
Force size and structure
Military Organization
Warhead production/maintenance facilities; industrial base; test facilities
Declaratory policy
Command and control; early warning; ISR; targeting
Troops; training; procedures; operations
Enabling systems
Deployed and reserve systems; readiness status
Statements; training and exercises; domestic discourse
War plans
Treaty obligations
Questions raised by reductions
• Can U.S. fulfill “deterrence” requirements?
Will weapons reach target?
Will weapons destroy target?
Reliability; pre- and post-launch survivability
Yield, accuracy and target location error
Can requirements be revised?
How will allies/adversaries view U.S. resolve and capability?
What will the effects on “strategic stability” be?
Current U.S. force structure
(Silo based)
Minuteman III
W78; W87
Ohio-class SSBN
W76-0/1; W88
Heavy Bombers
(Gravity bombs)
B61-7/11; B83-1
(+ gravity bombs)
F-15E; F-16C/D
(Gravity bombs)
“Tactical” fighters
Future of the triad
• Political context crucial; in practice force structure will be
determined by politics of the moment as much as nuclear
ICBM replacement will probably be delayed further (beyond
2020); early abandonment very unlikely (jobs!)
Very strong support for SLBMs
Multiple decision points related to heavy bombers and tactical
fighters coming up
• Air leg most vulnerable
Arguments for heavy bombers
and tactical fighters
• Unique ability to hold buried targets at risk
But, how much do these targets really matter?
• Stealth as alternative to speed for defense penetration
But, how likely is effective BMD?
• Recallable
But, how many war plan options include only aircraft?
• Forward deployment as tool for assurance
But, are there alternatives?
• Signaling as tool for crisis management
A growing role for conventional weapons in
strategic war plans?
DoD is directed to conduct deliberate planning for non-nuclear strike
options to assess what objectives and effects could be achieved
through integrated non-nuclear strike options, and to propose possible
means to make these objectives and effects achievable. Although they
are not a substitute for nuclear weapons, planning for non-nuclear
strike options is a central part of reducing the role of nuclear weapons.
Report on Nuclear Employment Strategy of the United States (2013)
Probably not about large-scale replacement.
Types of target in a “counterforce” attack
against North Korea
• Fixed, soft targets
ICBM sitting on a launch pad
• Fixed, buried targets
Warhead storage facilities; leadership; command and control
Probably tens, potentially hundreds of metres deep
• Mobile, soft targets
Road-mobile missiles
Massive ordnance penetrator
• Total mass: 13,600 kg
• HE mass: 2,400 kg
• Can reportedly
penetrate to 20 m in
reinforced concrete
(much less than
nuclear weapons)
Physics of conventional penetrators
Young Penetration Equation (SI Units)

 = 0.000018  

 − 30.5
D: Depth
S: Penetrability of target
N: Nose performance coefficient
m: Mass
A: Cross sectional area
V: Speed
From Nelson (2002)
CPGS technological approaches
Comparison of penetrator effectiveness

 = 0.000018  

 − 30.5
V (m/s)
500 [?]
m/A (kg/m)
• Ratio of penetration depths: 1.3-2.1
• CPGS penetrator would only contain about 10% of
the HE that MOP does.
Mobile missile hunting
Need to locate and track missiles
If using standoff weapons need to provide inflight target updates
(or risk waiting until they’re stationary)
North Korea has hundreds of mobile ballistic missiles
Only a small fraction might contain a nuclear warhead, but very hard to tell
which is which
1991 Gulf War: 1,460 sorties; 0 confirmed kills
2006 Israel-Hizbollah war: 80-90% of Hizbollah’s medium- and longrange rocket launchers destroyed. But, took time and relied on
attacking launchers after missiles has fired.
Nuclear v. conventional options
• Lethal radius from flechette weapon: <100 m, possibly
much less (my calculation)
TEL can traverse this distance in 10 s
• Lethal radius from 100 kT nuclear weapon: 2,900 m
(McKinzie et al. 2001)
TEL can traverse this distance in 260 s
• Hunting mobile missiles with conventional weapons much
harder than nuclear weapons

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