Future nuclear weapon policies James M. Acton
[email protected]
(Some) elements of nuclear posture •
Force size and structure •
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Military Organization •
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Warhead production/maintenance facilities; industrial base; test facilities
Declaratory policy •
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Command and control; early warning; ISR; targeting
Infrastructure •
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Troops; training; procedures; operations
Enabling systems •
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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? •
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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 Platform
Missile
Warhead
ICBM
(Silo based)
Minuteman III
W78; W87
SLBM
Ohio-class SSBN
Trident-D5
W76-0/1; W88
Heavy Bombers
B-2
(Gravity bombs)
B61-7/11; B83-1
B-52H
ALCM
W80-1 (+ gravity bombs)
F-15E; F-16C/D
(Gravity bombs)
B61-3/4/10
“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 strategy •
• •
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)
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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) 𝑚 𝐷 = 0.000018 𝑆 𝑁 𝐴
0.7
𝑉 − 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 𝑚 𝐷 = 0.000018 𝑆 𝑁 𝐴
0.7
𝑉 − 30.5
MOP
CPGS
V (m/s)
500 [?]
1,000-1,200
m/A (kg/m)
27,000
14,000-21,000
• 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:
