stanford mse293 national security: lecture 3

8/14/2019 Stanford MSE293 National Security: Lecture 3

1/49

Nuclear Weapons:

Effects, Systems, Cold WarHistoryMichael May

MS and E 1/2933 October 2005


2/49

2

The Basic Fact for Nuclear

Policy One nuclear explosion, easily delivered,

not hard to make, destroys:

One city or

One airbase or port or

One aircraft carrier

Question: can a war be won against anation armed with nuclear weapons?


3/49

3

Once and Current Thinking

Nuclear weapons are weapons likeothers, to be used to win wars (minority

view, cannot be wholly avoided) Nuclear weapons make war obsolete, to

be used as deterrents only (majorityview in all nuclear-armed states so far)

Nuclear weapons require a basicchange in how nations deal with eachother if catastrophe is to be avoided

(view of Einstein, US bishops, others)


4/49

4

Outline of Lecture

I. Nuclear Weapons and Effects

II. Nuclear Weapon Systems, Deterrence

III. Nuclear Arms Control

IV. Why Do Countries Get or Dont GetNuclear Weapons


5/49

5

I. Weapons and Effects


6/49

6

Chain Reaction, Critical

Mass, U-235 and Plutonium At least 1 fission

neutron must causeanother fission for achain reaction to go

The critical massdepends on material,geometry, density

If > 1 fission neutroncauses fission, thereaction is explosive


7/49

7

Whats Difficult?

Only rare natural isotopes (U-235, Th-233)and artificial element Plutonium are able tosustain a fast chain reaction

Separating these isotopes or making Pu arethe main cost of making weapons

A successful weapon program can cost


8/49

8

A Mushroom Cloud

Bravo Test

Yield: 15Mt

Location: Bikini

Date: 28.Feb.1954


9/49

9

The Cloud Over Nagasaki

August 9, 1945 Of the 286,000 people

living in Nagasaki atthe time of the blast, 60-80,000 were killed atonce.

At Hiroshima, about 90-140,000 out of 310,000

were killed at once. Similar numbers were

seriously injured


10/49

10

Blast

The pressure wave is the most reliabledamage mechanism to structures, has

been the basis for military targeting. It is most effective if the explosion

occurs at the optimum height of burst,which eliminates fallout.

The distance at which a given damageoccurs increases slowly with yield.


11/49

11

Heat

Heat can be more destructive than blast,given clear weather and flammability.

Some calculations show that firestormswould occur in most cities.

Heat is not effective against many

military structures or protectedpersonnel.


12/49

12

Radioactivity

Prompt Radioactivity (Immediateexplosion)

Matters most for low yields (< 10 kt) Can be shielded against

Fallout

Generated by ground bursts Pattern depends on wind and rain

High yields (> 1 Mt) carried globally


13/49

13

Fire/blast (solid) and Fallout(line) from 10 kt ground burst in

San Francisco (50% lethality)


14/49

14

Electromagnetic Effects

A single high-altitude explosion could disablemany computers, satellites, etc.

Military (including nuclear) command,communication and control as well as radarscould be affected.

Shielding is feasible but requires considerable

care, in part because of the short time ofenergy generation.


15/49

15

EMP Effect Over US

In 1962, a high-altitude detonation

caused street lights,power circuits, etc.1300 km away to fail

EMP effects have

not been thoroughlyinvestigated

Surprises are likely


16/49

16

Global Effects from Large-

Scale Nuclear War Climate: nuclear winter unlikely,

more local climatic effects possible

Global Fallout: due mainly to high-yield ground bursts e.g. againsthardened structures such as silos

Bio-environmental Unknowns: likelyto matter, very difficult to research

Targeted countries suffer most damage


17/49

17

What Would Really Happen?

Could a large metropolitan areafunction after one nuclear explosion?

How long before functioning isrestored, and what factors affect that?

What preparations would help?

These questions, once urgent, havecome up again in connection withterrorism.


18/49

18

II. Nuclear Weapon Systems,Deterrence


19/49

19

Deployment History

Starting in the Eisenhower era, over athousand ICBMs, hundreds of bombers,

and hundreds of SLBMs weredeployed. These made up the Triad.

MIRVs multiplied these numbers to

where over 10,000 nuclear weaponswere deployed on each side.


20/49

20

Scale of Nuclear Weapons

Note scale of RV

Each RV in the

missile contains oneweapon

The yield is tens oftimes Hiroshimayield

A submarine canlaunch >20 missiles


21/49

21

The Weapons Systems Had

to Survive If they did not, they could not deter. Indeed,

survivability on both sides was needed fordeterrence to work stably.

ICBMs in hard silos gradually becamevulnerable to accurate MIRVs.

Subs were made ever more quiet.

Bombers were kept on alert. Communications and control were duplicated

and hardened but remained in question


22/49

22

The Results

Large numbers of US and Russiannuclear forces would have survived

nuclear attack. Most of the nuclear budget was spent

on survivability, perhaps $4 of $5 T.

Survivability of C3 was harder to prove.

Possible reliance on launch-on-warningfor vulnerable missiles remains a

danger.


23/49

23

Why So Many?

Politics: to argue for fewer did not winelections in a climate of uncertainty

Service rivalries: the main branches ofservice involved had similar numbers

Worst case analysis: while intelligence

put a cap on what the other side haddone, the future was often estimated ona worst-case assumption.


24/49

24

Did Nuclear Deterrence Keep

the Peace (1)? Most analysts think it at least helped:

There is little or no precedent for a rivalry

like the Cold War NOT leading to war Many instances of leaders being cautious

about taking any risk of nuclear war exist

Unlike the earlier part of the century, andperhaps unlike today, no political leaderadvocated war to his people


25/49

25

Did Nuclear Deterrence Keep

the Peace (2)? On the other hand, many note:

The US and the Soviet Union were far

apart with quite distinct spheres of power Their conventional forces confronted each

other far away from the homelands

Territorial ambitions on either side were

limited and well-understood Thus the context mattered to make

deterrence stable and limit crises


26/49

26

III. Nuclear Arms Control


27/49

27

Arms Control:

The SALT Agreements By the late 60s, the US was coming

down from >20,000 weapons and the

Soviet Union going up from 10,000 Some limit was agreed to be needed

The SALT treaties (1972-79):

Froze the strategic offensive numbers Prevented an effective ABM system

Did not limit tactical nuclear weapons


28/49

28

Arms Control: The START

Treaties and SORT START I (1991-4) cut strategic arms by about

half, removed them from Ukraine, Byelarusand Kazhakstan. Now void.

START II (1993-2000) would have cutanother 30% by 2004. No MIRVed ICBMs.Aborted.

SORT (2002) cut operational strategicnuclear weapons by 30-45% more to 1500-2000 by 2007. Ten year duration. Noverification provision. Reserve, tacticalweapons not limited.


29/49

29

Excess Nuclear Weapon

Materials Overproduction and reductions have

led to large quantities of surplus

fissilematerials: At least 1000 tons of HEU and 100 tons of

Pu: enough for >104 weapons

Directly usable materials Nearly all in the US and the FSU states

Some of it under poor or unknown control


30/49

30

Excess Nuclear Weapon

Materials This material, along with Pakistani weapons,

constitutes the greatest terrorism danger

The US has had programs to either get rid ofit or put it under better control, but theseprograms are going slowly because offinancial and political limitations

Other countries did little, though this maychange following a G-8 resolution and morerecent initiatives


31/49

31

Arms Control:

The Nuclear Test Bans Attempting to ban nuclear tests dates back to

the 50s

An important driver was the fear of fallout,which was eliminated with the Limited TestBan Treaty of 1963 (LTBT) John Kennedy

A Comprehensive Test Ban Treaty (CTBT)has been signed but cannot come into forceuntil the US and 43 other specified statesratify it


32/49

32

Arguments For a CTBT

A CTBT would:

Prevent significantly new weapon

designs in the NWS or any advanceddesign (e.g., thermonuclear) elsewhere

Help fulfill NWS obligations under

NPT and thereby bolster the regime Not adversely affect present stockpiles

Be verifiable in all important respects


33/49

33

Arguments for Nuclear

Testing Stockpile weapons change (changing

military and safety requirements,

deterioration, inability to make exactcopies). Uncertainty in performanceincreases with each change.

Nuclear laboratories personnel will losetheir ability to make changes reliably.

Verification under 1 KT is not assured.


34/49

34

Status of the CTBT

The US Senate rejected the CTBT and thepresent administration does not support it.

Most states have signed the CTBT and anumber have ratified it.

It cannot enter into force until the US andspecified other states ratify it.

Moratorium on nuclear testing has held since1996 except for India, Pakistan (1998)

New weapons under consideration in the USmay require nuclear tests.


35/49

35

IV. Why Do Countries Get orDont Get Nuclear Weapons


36/49

36

Atoms for Peace

Fifty years ago, President Eisenhowerproposed a grand bargain that has been

largely followed but needs updating: The nations that did not have nuclear

weapons would abstain

In return, those that did would help theothers with civilian applications

An international organization wouldmonitor the bargain


37/49

37

Proliferation

Every state that got nuclear weapons did notwant other states to get them.

After the Permanent Five members of the UNSecurity Council got them, they proposed atreaty to prevent further proliferation.

It was not an equal treaty but was widely

adopted.

Why?


38/49

38

The Nuclear Non-

Proliferation Treaty (NPT) The NPT which came into force in 1970

and was extended indefinitely in 1995

provides for five nuclear weapon states(NWS): the US, China, France, the UKand the Soviet Union, now Russia.

All other signatories were to be non-nuclear weapon states (NNWS) underthe NPT


39/49

39

The Nuclear Non-

Proliferation Treaty (NPT) Today all states are signatories except

India, Israel, and Pakistan, all of which

have nuclear weapons, and NorthKorea which has withdrawn.

A number of other states started NW

programs. A few of them (North Korea,perhaps Iran) are continuing.


40/49

40

The Nuclear Non-

Proliferation Treaty (NPT) The NWS agree to work toward the

elimination of all nuclear weapons and toassist the NNWS in obtaining the civilian

benefits of nuclear energy The NWS agree not to acquire nuclear

weapons

In associated declarations, the NWS statedthey would not attack or threaten the NNWSwith nuclear weapons except under certainconditions


41/49

41

The IAEA

The NPT is supported by other agreementsand institutions, such as the IAEA, whichmonitors compliance in the civilian nuclearsector, and the NSG, which controls exports

These institutions have come under firebecause of North Korean and Iraqi cheating

The IAEA has only as much power as theparties give it. In particular: It has no enforcement power

Its inspection powers depend on agreement


42/49

42

The IAEA

Where political situations permitted,the IAEA has done a good job at its

assigned tasks There are a number of technical ways to

strengthen its oversight of facilities and

materials that depend mainly onpolitical agreements and someinvestment for their implementation


43/49

43

The IAEA

Eisenhowers grand bargain held aslong as nuclear weapons and materials

were difficult to get. This is no longer true.

The bargain needs updating if civilian

nuclear applications of all kinds are tobe compatible with internationalsecurity.


44/49

44

Whats Wrong with the NPT?

A state can get most of the way to anuclear weapon as a NNWS, then leave

There is no penalty for withdrawingafter cheating

Israel, India and Pakistan are not in

There has been and may still be a blackmarket in nuclear weapons technology


45/49

45

Some Recent Initiatives to

Fix the NPT No new enrichment or separation

facilities (Bush) or put them under

international control (ELBaradei) Criminalizing nuclear weapon trade

(UNSC) in uniform way around world.

Cooperating to stop illegal trade (PSI)(Bush), very difficult

Enforcement remains an open question

Who?


46/49

46

First NuclearTest

# Nuclear

Weapons

Status

US 1945 12,000 NPT NWS

Russia 1949 22,000 NPT NWS

UK 1952 260 NPT NWSFrance 1960 450 NPT NWS

China 1964 400 NPT NWS

Israel ? About 100 Non-NPT

NWS

India 1973 About 100

unassembled?

Non-NPT

NWS

Pakistan 1998 10-20

unassembled?

Non-NPT

NWS

North Korea None 0-10 NPT NNWS

Iraq None 0, program

forcibly

stopped

NPT NNWS

Iran, Brazil,Japan,

None 0, dual useprograms

NPT NNWS

SA, Ukr, Kaz,

Byel

? 0, gave up

NW

NPT NNWS

About 7 Others None 0, gave up

NW programs

NPT NNWS

About 20

Others

None 0, civil

reactors

NPT NNWS

Who?

Wh ?


47/49

47

Why?

State Likely Contingent Reason

US Hitler, later Soviet Union,now?

Soviet Union/Russia US

France, UK To remain great powers

China US, Soviet Union

Israel Arabs

India Domestic preference, prestige,China

Pakistan India; Muslim bomb

North Korea Deter US, bargaining chip?

Iraq Deter Iran, Arab leadership?

Various present and former

suspects

Deter neighbors and/or US,

prestige, bargaining chip?All others No utility, not worth the cost;

could change with security

perceptions


48/49

48

The Larger Framework of

Nuclear Security Nuclear non-proliferation did not work by

itself, it worked within a particular economic

and political framework The West built a sphere of relative prosperity

and security within which nuclearproliferation usually made no sense

Now that more countries can build weapons,the context of prosperity and security remainsessential to successful non-proliferation


49/49

So How Was Our Original

Question Answered? There was nuclear deterrence but no nuclear

war: both the US and the Soviet Union madethat the first order of business.

Too many weapons and weapon materialwere made, which remain to haunt us to thisday.

The US won a cold peace. Now nuclear weapons may become as muchequalizers as tools of deterrence

Einsteins quandary remains

stanford mse293 national security: lecture 3

Documents