☢ MOD 15: Nuclear Weapons and U.S. Foreign Policy II

I. The Problem of Credibility in Nuclear Deterrence

A. Definition and Significance

• Deterrence relies on convincing an adversary that retaliation for an attack would be certain and catastrophic.

• The credibility problem arises because nuclear war is so destructive that it is not believable a state would actually carry out a retaliatory strike once attacked.

• Therefore, threats must appear credible, even when following through would be irrational.

B. Why Credibility Matters

• If a rival doubts that the defender will respond, deterrence fails and war becomes more likely.

• Example: During the Cold War, the U.S. had to convince the Soviet Union it would use nuclear weapons if NATO was attacked, even though that risked U.S. destruction.

• Nuclear deterrence depends on belief—the perception of willingness, not just capability.

C. The Logic of the Credibility Dilemma

1. Paradox:

   • Using nuclear weapons is irrational due to catastrophic costs, but threatening to use them must seem rational for deterrence to work.

2. Result:

   • States engage in credibility signaling to make their deterrent threats believable.

II. Extended Deterrence

A. Definition

• Extended deterrence refers to a state’s commitment to protect its allies or partners from attack using nuclear retaliation.

• Example: The U.S. protecting Western Europe and Japan during the Cold War.

B. The Credibility Challenge

• The defender must convince both allies and adversaries that it will risk its own cities to protect another country.

• This raises doubts: would the U.S. really risk New York to save Paris?

C. Historical Response

• Because of these doubts, some U.S. allies developed their own nuclear weapons:

  • United Kingdom (1952)

  • France (1960)

• These programs ensured their own deterrent capability in case U.S. promises failed.

III. Foundations of Credibility: Capabilities and Resolve

A. Capabilities

• The material ability to execute a nuclear strike.

• Includes:

  • Weapons stockpiles

  • Delivery systems (ICBMs, bombers, submarines)

  • Command, control, and communication systems

• Without reliable capabilities, threats lose credibility entirely.

B. Resolve

• Resolve is the willingness to carry out the threat despite the risks.

• Harder to measure than capabilities—it is shown through behavior and signaling.

• Strong resolve increases deterrence even with smaller arsenals.

C. Combined Effect

• Deterrence credibility = Capabilities × Resolve

• Example: North Korea’s small arsenal still deters the U.S. because it demonstrates both (tests = capability, rhetoric = resolve).

IV. Demonstrating Credibility in Nuclear Deterrence

A. Key Strategies to Signal Resolve

1. Brinkmanship

   • Deliberately pushing crises to the edge of war to force an opponent to back down.

   • Shows that the state is willing to take risks to defend its interests.

   • Example: The Cuban Missile Crisis (1962)—Kennedy’s naval blockade and public stand signaled U.S. willingness to escalate.

2. Tripwire Forces

   • Deploying small military units in allied territories.

   • Guarantees that any attack automatically involves the protecting power.

   • Example: U.S. troops stationed in West Germany during the Cold War ensured automatic American involvement if the USSR invaded.

3. “The Threat That Leaves Something to Chance”

   • Introduced by Thomas Schelling.

   • A strategy where leaders create a small risk of accidental escalation to show seriousness.

   • The fear of unintended war makes the threat more credible to adversaries.

4. Public Pronouncements by Democracies

   • Democratic leaders often make public commitments that raise domestic and international reputational costs if they back down.

   • Public opinion, press scrutiny, and electoral consequences reinforce credibility.

V. National Missile Defense (NMD) and Stability

A. Basic Concept

• NMD systems attempt to intercept and destroy incoming ballistic missiles before they reach their targets.

• Examples:

  • Reagan’s Strategic Defense Initiative (SDI) in the 1980s (“Star Wars”).

  • Modern U.S. systems focus on small threats (e.g., North Korea).

B. Relationship to Mutual Deterrence

• Nuclear deterrence stability depends on Mutually Assured Destruction (MAD): both sides must maintain a secure second-strike capability.

• NMD threatens this balance if one side believes it can block retaliation, undermining MAD.

C. Destabilizing Effects

1. Protected State’s Behavior:

   • Might act more aggressively, thinking it can avoid retaliation.

2. Vulnerable State’s Behavior:

   • Might expand its arsenal or strike preemptively before the defense system matures.

D. U.S. Policy

• The U.S. currently maintains limited NMD to protect against small arsenals or accidental launches, not to neutralize major powers like Russia or China.

VI. Nuclear Proliferation

A. Definition

• Nuclear proliferation: the spread of nuclear weapons technology to additional states beyond the original nuclear powers.

B. Why States Seek Nuclear Weapons

1. Security Concerns

   • Fear of external threats or distrust of alliances.

   • Example: North Korea’s pursuit of nukes due to regime survival fears.

2. Domestic Politics

   • Leaders may use nuclear programs to gain prestige or consolidate internal power.

3. International Status

   • Nuclear capability increases a state’s influence and bargaining power globally.

C. Why the U.S. and Others Oppose Proliferation

1. Crisis Instability

   • New nuclear states often lack robust command-and-control systems.

   • Increases risk of accidental launches or unauthorized use.

2. Terrorism and Theft

   • More nuclear material increases the risk of proliferation to non-state actors.

3. Regional Arms Races

   • New nuclear powers often provoke neighbors to start their own programs.

   • Example: India–Pakistan nuclear competition.

4. Global Stability

   • More nuclear-armed states = more unpredictable behavior and higher chance of miscalculation.

D. Preventing Proliferation

• Tools include:

  • Treaties: Non-Proliferation Treaty (NPT, 1968).

  • Sanctions and diplomacy.

  • Security guarantees (U.S. alliances that reduce incentives to develop independent arsenals).

VII. Summary and Key Takeaways

• Credibility is central to nuclear deterrence — threats must be believable despite catastrophic costs.

• Extended deterrence complicates credibility because protecting allies risks self-destruction.

• Capabilities + resolve determine whether deterrence works.

• States use brinkmanship, tripwire forces, chance-based threats, and public promises to demonstrate resolve.

• Missile defense systems can both enhance protection and destabilize deterrence by undermining mutual vulnerability.

• Nuclear proliferation creates long-term instability and increases global risk, driving non-proliferation efforts and alliances.